Author: Graeme Birchall ©
Email: Graeme_Birchall@verizon.net
Web: http://mysite.verizon.net/Graeme_Birchall/
Title: DB2 9.5 SQL Cookbook ©
Date: 1-Dec-2008
EMP_NM EMP_JB SELECT nm.id ANSWER
+----------+ +--------+ ,nm.name ================
|ID|NAME | |ID|JOB | ,jb.job ID NAME JOB
|--|-------| |--|-----| FROM emp_nm nm -- ------- -----
|10|Sanders| |10|Sales| ,emp_jb jb 10 Sanders Sales
|20|Pernal | |20|Clerk| WHERE nm.id = jb.id 20 Pernal Clerk
|50|Hanes | +--------+ ORDER BY 1;
+----------+
Figure 1, Join example
EMP_NM EMP_JB SELECT nm.id ANSWER
+----------+ +--------+ ,nm.name ================
|ID|NAME | |ID|JOB | ,jb.job ID NAME JOB
|--|-------| |--|-----| FROM emp_nm nm -- ------- -----
|10|Sanders| |10|Sales| LEFT OUTER JOIN 10 Sanders Sales
|20|Pernal | |20|Clerk| emp_jb jb 20 Pernal Clerk
|50|Hanes | +--------+ ON nm.id = jb.id 50 Hanes -
+----------+ ORDER BY nm.id;
Figure 2,Left-outer-join example
EMP_NM EMP_JB SELECT * ANSWER
+----------+ +--------+ FROM emp_nm nm ========
|ID|NAME | |ID|JOB | WHERE NOT EXISTS ID NAME
|--|-------| |--|-----| (SELECT * == =====
|10|Sanders| |10|Sales| FROM emp_jb jb 50 Hanes
|20|Pernal | |20|Clerk| WHERE nm.id = jb.id)
|50|Hanes | +--------+ ORDER BY id;
+----------+
Figure 3, Sub-query example
EMP_NM EMP_JB SELECT * ANSWER
+----------+ +--------+ FROM emp_nm =========
|ID|NAME | |ID|JOB | WHERE name < 'S' ID 2
|--|-------| |--|-----| UNION -- ------
|10|Sanders| |10|Sales| SELECT * 10 Sales
|20|Pernal | |20|Clerk| FROM emp_jb 20 Clerk
|50|Hanes | +--------+ ORDER BY 1,2; 20 Pernal
+----------+ 50 Hanes
Figure 4, Union example
EMP_JB SELECT id
+--------+ ,job ANSWER
|ID|JOB | ,ROW_NUMBER() OVER(ORDER BY job) AS R ==========
|--|-----| FROM emp_jb ID JOB R
|10|Sales| ORDER BY job; -- ----- -
|20|Clerk| 20 Clerk 1
+--------+ 10 Sales 2
Figure 5, Assign row-numbers example
EMP_JB SELECT id ANSWER
+--------+ ,job ===============
|ID|JOB | ,CASE ID JOB STATUS
|--|-----| WHEN job = 'Sales' -- ----- ------
|10|Sales| THEN 'Fire' 10 Sales Fire
|20|Clerk| ELSE 'Demote' 20 Clerk Demote
+--------+ END AS STATUS
FROM emp_jb;
Figure 6, Case stmt example
FAMILY WITH temp (persn, lvl) AS ANSWER
+-----------+ (SELECT parnt, 1 =========
|PARNT|CHILD| FROM family PERSN LVL
|-----|-----| WHERE parnt = 'Dad' ----- ---
|GrDad|Dad | UNION ALL Dad 1
|Dad |Dghtr| SELECT child, Lvl + 1 Dghtr 2
|Dghtr|GrSon| FROM temp, GrSon 3
|Dghtr|GrDtr| family GrDtr 3
+-----------+ WHERE persn = parnt)
SELECT *
FROM temp;
Figure 7, Recursion example
INPUT DATA Recursive SQL ANSWER
================= ============> ===========
"Some silly text" TEXT LINE#
----- -----
Some 1
silly 2
text 3
Figure 8, Convert string to rows
INPUT DATA Recursive SQL ANSWER
=========== ============> =================
TEXT LINE# "Some silly text"
----- -----
Some 1
silly 2
text 3
Figure 9, Convert rows to string
EMP_NM SELECT * ANSWER
+----------+ FROM emp_nm =========
|ID|NAME | ORDER BY id DESC ID NAME
|--|-------| FETCH FIRST 2 ROWS ONLY; -- ------
|10|Sanders| 50 Hanes
|20|Pernal | 20 Pernal
|50|Hanes |
+----------+
Figure 10, Fetch first "n" rows example
EMP_NM SELECT * ANSWER
+----------+ FROM emp_nm ==========
|ID|NAME | WHERE name like 'S%' ID NAME
|--|-------| WITH UR; -- -------
|10|Sanders| 10 Sanders
|20|Pernal |
|50|Hanes |
+----------+
Figure 11, Fetch WITH UR example
EMP_NM SELECT AVG(id) AS avg ANSWER
+----------+ ,MAX(name) AS maxn =================
|ID|NAME | ,COUNT(*) AS #rows AVG MAXN #ROWS
|--|-------| FROM emp_nm; --- ------- -----
|10|Sanders| 26 Sanders 3
|20|Pernal |
|50|Hanes |
+----------+
Figure 12, Column Functions example
SELECT job ANSWER
,dept ==========================
,SUM(salary) AS sum_sal JOB DEPT SUM_SAL #EMPS
,COUNT(*) AS #emps ----- ---- --------- -----
FROM staff Clerk 15 84766.70 2
WHERE dept < 30 Clerk 20 77757.35 2
AND salary < 90000 Clerk - 162524.05 4
AND job < 'S' Mgr 10 243453.45 3
GROUP BY ROLLUP(job, dept) Mgr 15 80659.80 1
ORDER BY job Mgr - 324113.25 4
,dept; - - 486637.30 8
Figure 13, Subtotal and Grand-total example
Figure 14, Syntax Diagram Conventions
SELECT name -- this is a comment.
FROM staff -- this is another comment.
ORDER BY id;
Figure 15, SQL Comment example
--#SET DELIMITER !
SELECT name FROM staff WHERE id = 10!
--#SET DELIMITER ;
SELECT name FROM staff WHERE id = 20;
Figure 16, Set Delimiter example
CREATE TABLE employee
(empno CHARACTER (00006) NOT NULL
,firstnme VARCHAR (00012) NOT NULL
,midinit CHARACTER (00001) NOT NULL
,lastname VARCHAR (00015) NOT NULL
,workdept CHARACTER (00003)
,phoneno CHARACTER (00004)
,hiredate DATE
,job CHARACTER (00008)
,edlevel SMALLINT NOT NULL
,SEX CHARACTER (00001)
,birthdate DATE
,salary DECIMAL (00009,02)
,bonus DECIMAL (00009,02)
,comm DECIMAL (00009,02)
)
DATA CAPTURE NONE;
Figure 17, DB2 sample table - EMPLOYEE
CREATE VIEW employee_view AS
SELECT a.empno, a.firstnme, a.salary, a.workdept
FROM employee a
WHERE a.salary >=
(SELECT AVG(b.salary)
FROM employee b
WHERE a.workdept = b.workdept);
Figure 18, DB2 sample view - EMPLOYEE_VIEW
CREATE VIEW silly (c1, c2, c3)
AS VALUES (11, 'AAA', SMALLINT(22))
,(12, 'BBB', SMALLINT(33))
,(13, 'CCC', NULL);
Figure 19, Define a view using a VALUES clause
SELECT c1, c2, c3 ANSWER
FROM silly ===========
ORDER BY c1 aSC; C1 C2 C3
-- --- --
11 AAA 22
12 BBB 33
13 CCC -
Figure 20, SELECT from a view that has its own data
CREATE VIEW test_data AS
WITH temp1 (num1) AS
(VALUES (1)
UNION ALL
SELECT num1 + 1
FROM temp1
WHERE num1 < 10000)
SELECT *
FROM temp1;
Figure 21, Define a view that creates data on the fly
CREATE ALIAS employee_al1 FOR employee;
COMMIT;
CREATE ALIAS employee_al2 fOR employee_al1;
COMMIT;
CREATE ALIAS employee_al3 FOR employee_al2;
COMMIT;
Figure 22, Define three aliases, the latter on the earlier
CREATE NICKNAME emp FOR unixserver.production.employee;
Figure 23, Define a nickname
SELECT *
FROM staff TABLESAMPLE BERNOULLI(10);
Figure 24, TABLESAMPLE example
CREATE TABLE sales_record
(sales# INTEGER NOT NULL
GENERATED ALWAYS AS IDENTITY
(START WITH 1
,INCREMENT BY 1
,NO MAXVALUE
,NO CYCLE)
,sale_ts TIMESTAMP NOT NULL
,num_items SMALLINT NOT NULL
,payment_type CHAR(2) NOT NULL
,sale_value DECIMAL(12,2) NOT NULL
,sales_tax DECIMAL(12,2)
,employee# INTEGER NOT NULL
,CONSTRAINT sales1 CHECK(payment_type IN ('CS','CR'))
,CONSTRAINT sales2 CHECK(sale_value > 0)
,CONSTRAINT sales3 CHECK(num_items > 0)
,CONSTRAINT sales4 FOREIGN KEY(employee#)
REFERENCES staff(id) ON DELETE RESTRICT
,PRIMARY KEY(sales#));
Figure 25, Sample table definition
CREATE TABLE default_values
(c1 CHAR NOT NULL
,d1 DECIMAL NOT NULL);
Figure 26, Table with default column lengths
SELECT DECFLOAT(+1.23) + NaN AS " NaN"
,DECFLOAT(-1.23) + NaN AS " NaN"
,DECFLOAT(-1.23) + -NaN AS " -NaN"
,DECFLOAT(+infinity) + NaN AS " NaN"
,DECFLOAT(+sNaN) + NaN AS " NaN"
,DECFLOAT(-sNaN) + NaN AS " -NaN"
,DECFLOAT(+NaN) + NaN AS " NaN"
,DECFLOAT(-NaN) + NaN AS " -NaN"
FROM sysibm.sysdummy1;
Figure 27, NaN arithmetic usage
SELECT DECFLOAT(1) / +infinity AS " 0E-6176"
,DECFLOAT(1) * +infinity AS " Infinity"
,DECFLOAT(1) + +infinity AS " Infinity"
,DECFLOAT(1) - +infinity AS "-Infinity"
,DECFLOAT(1) / -infinity AS " -0E-6176"
,DECFLOAT(1) * -infinity AS "-Infinity"
,DECFLOAT(1) + -infinity AS "-Infinity"
,DECFLOAT(1) - -infinity AS " Infinity"
FROM sysibm.sysdummy1;
Figure 28, Infinity arithmetic usage
SELECT DECFLOAT(+1.23) / 0 AS " Infinity"
,DECFLOAT(-1.23) / 0 AS "-Infinity"
,DECFLOAT(+1.23) + infinity AS " Infinity"
,DECFLOAT(0) / 0 AS " NaN"
,DECFLOAT(infinity) + -infinity AS " NaN"
,LOG(DECFLOAT(0)) AS "-Infinity"
,LOG(DECFLOAT(-123)) AS " NaN"
,SQRT(DECFLOAT(-123)) AS " NaN"
FROM sysibm.sysdummy1;
Figure 29, DECFLOAT arithmetic results
-NaN -sNan -infinity -1.2 -1.20 0 1.20 1.2 infinity sNaN NaN
Figure 30, DECFLOAT value order
ANSWER
WITH temp1 (d1, d2) AS ======
(VALUES (DECFLOAT(+1.0), DECFLOAT(+1.00)) 1
,(DECFLOAT(-1.0), DECFLOAT(-1.00)) -1
,(DECFLOAT(+0.0), DECFLOAT(+0.00)) 1
,(DECFLOAT(-0.0), DECFLOAT(-0.00)) 1
,(DECFLOAT(+0), DECFLOAT(-0)) 0
)
SELECT TOTALORDER(d1,d2)
FROM temp1;
Figure 31, Equal values that may have different orders
WITH temp1 (d1) AS
(VALUES (DECFLOAT(+0 ,16))
,(DECFLOAT(+0.0 ,16))
,(DECFLOAT(+0.00 ,16))
,(DECFLOAT(+0.000 ,16))
)
SELECT d1
,HEX(d1) AS hex_d1
,NORMALIZE_DECFLOAT(d1) AS d2
,HEX(NORMALIZE_DECFLOAT(d1)) AS hex_d2
FROM temp1;
ANSWER
==========================================
D1 HEX_D1 D2 HEX_D2
----- ---------------- -- ----------------
0 0000000000003822 0 0000000000003822
0.0 0000000000003422 0 0000000000003822
0.00 0000000000003022 0 0000000000003822
0.000 0000000000002C22 0 0000000000003822
Figure 32, Remove trailing zeros
LABELED DURATIONS ITEM WORKS WITH DATE/TIME
<------------------------> FIXED <--------------------->
SINGULAR PLURAL SIZE DATE TIME TIMESTAMP
=========== ============ ===== ==== ==== =========
YEAR YEARS N Y - Y
MONTH MONTHS N Y - Y
DAY DAYS Y Y - Y
HOUR HOURS Y - Y Y
MINUTE MINUTES Y - Y Y
SECOND SECONDS Y - Y Y
MICROSECOND MICROSECONDS Y - Y Y
Figure 33, Labeled Durations and Date/Time Types
ANSWER
==========
SELECT sales_date <= 1995-12-31
,sales_date - 10 DAY AS d1 <= 1995-12-21
,sales_date + -1 MONTH AS d2 <= 1995-11-30
,sales_date + 99 YEARS AS d3 <= 2094-12-31
,sales_date + 55 DAYS
- 22 MONTHS AS d4 <= 1994-04-24
,sales_date + (4+6) DAYS AS d5 <= 1996-01-10
FROM sales
WHERE sales_person = 'GOUNOT'
AND sales_date = '1995-12-31'
Figure 34, Example, Labeled Duration usage
ANSWER
==========
SELECT sales_date <= 1995-12-31
,sales_date + 2 MONTH AS d1 <= 1996-02-29
,sales_date + 3 MONTHS AS d2 <= 1996-03-31
,sales_date + 2 MONTH
+ 1 MONTH AS d3 <= 1996-03-29
,sales_date + (2+1) MONTHS AS d4 <= 1996-03-31
FROM sales
WHERE sales_person = 'GOUNOT'
AND sales_date = '1995-12-31';
Figure 35, Adding Months - Varying Results
DURATION-TYPE FORMAT NUMBER-REPRESENTS USE-WITH-D-TYPE
============= ============= ===================== ===============
DATE DECIMAL(8,0) yyyymmdd TIMESTAMP, DATE
TIME DECIMAL(6,0) hhmmss TIMESTAMP, TIME
TIMESTAMP DECIMAL(20,6) yyyymmddhhmmss.zzzzzz TIMESTAMP
Figure 36, Date/Time Durations
SELECT empno ANSWER
,hiredate ====================================
,birthdate EMPNO HIREDATE BIRTHDATE
,hiredate - birthdate ------ ---------- ---------- -------
FROM employee 000150 1972-02-12 1947-05-17 240826.
WHERE workdept = 'D11' 000200 1966-03-03 1941-05-29 240905.
AND lastname < 'L' 000210 1979-04-11 1953-02-23 260116.
ORDER BY empno;
Figure 37, Date Duration Generation
ANSWER
==========
SELECT hiredate <= 1972-02-12
,hiredate - 12345678. <= 0733-03-26
,hiredate - 1234 years
- 56 months
- 78 days <= 0733-03-26
FROM employee
WHERE empno = '000150';
Figure 38, Subtracting a Date Duration
SPECIAL REGISTER UPDATE DATA-TYPE
=============================================== ====== =============
CURRENT CLIENT_ACCTNG no VARCHAR(255)
CURRENT CLIENT_APPLNAME no VARCHAR(255)
CURRENT CLIENT_USERID no VARCHAR(255)
CURRENT CLIENT_WRKSTNNAME no VARCHAR(255)
CURRENT DATE no DATE
CURRENT DBPARTITIONNUM no INTEGER
CURRENT DECFLOAT ROUNDING MODE no VARCHAR(128)
CURRENT DEFAULT TRANSFORM GROUP yes VARCHAR(18)
CURRENT DEGREE yes CHAR(5)
CURRENT EXPLAIN MODE yes VARCHAR(254)
CURRENT EXPLAIN SNAPSHOT yes CHAR(8)
CURRENT FEDERATED ASYNCHRONY yes INTEGER
CURRENT IMPLICIT XMLPARSE OPTION yes VARCHAR(19)
CURRENT ISOLATION yes CHAR(2)
CURRENT LOCK TIMEOUT yes INTEGER
CURRENT MAINTAINED TABLE TYPES FOR OPTIMIZATION yes VARCHAR(254)
CURRENT MDC ROLLOUT MODE yes VARCHAR(9)
CURRENT OPTIMIZATION PROFILE yes VARCHAR(261)
CURRENT PACKAGE PATH yes VARCHAR(4096)
CURRENT PATH yes VARCHAR(2048)
CURRENT QUERY OPTIMIZATION yes INTEGER
CURRENT REFRESH AGE yes DECIMAL(20,6)
CURRENT SCHEMA yes VARCHAR(128)
CURRENT SERVER no VARCHAR(128)
CURRENT TIME no TIME
CURRENT TIMESTAMP no TIMESTAMP
CURRENT TIMEZONE no DECIMAL(6,0)
CURRENT USER no VARCHAR(128)
SESSION_USER yes VARCHAR(128)
SYSTEM_USER no VARCHAR(128)
USER yes VARCHAR(128)
Figure 39, DB2 Special Registers
SET CURRENT ISOLATION = RR;
SET CURRENT SCHEMA = 'ABC'; ANSWER
=======================
SELECT CURRENT TIME AS cur_TIME CUR_TIME CUR_ISO CUR_ID
,CURRENT ISOLATION AS cur_ISO -------- ------- ------
,CURRENT SCHEMA AS cur_ID 12:15:16 RR ABC
FROM sysibm.sysdummy1;
Figure 40, Using Special Registers
Figure 41, Create Distinct Type Syntax
CREATE DISTINCT TYPE JAP_YEN AS DECIMAL(15,2) WITH COMPARISONS;
DROP DISTINCT TYPE JAP_YEN;
Figure 42, Create and drop distinct type
CREATE TABLE customer
(id INTEGER NOT NULL
,fname VARCHAR(00010) NOT NULL WITH DEFAULT ''
,lname VARCHAR(00015) NOT NULL WITH DEFAULT ''
,date_of_birth DATE
,citizenship CHAR(03)
,usa_sales DECIMAL(9,2)
,eur_sales DECIMAL(9,2)
,sales_office# SMALLINT
,last_updated TIMESTAMP
,PRIMARY KEY(id));
Figure 43, Sample table, without distinct types
SELECT id
,usa_sales + eur_sales AS tot_sales
FROM customer;
Figure 44, Silly query, but works
CREATE DISTINCT TYPE USA_DOLLARS AS DECIMAL(9,2) WITH COMPARISONS;
CREATE DISTINCT TYPE EUR_DOLLARS AS DECIMAL(9,2) WITH COMPARISONS;
Figure 45, Create Distinct Type examples
CREATE TABLE customer
(id INTEGER NOT NULL
,fname VARCHAR(00010) NOT NULL WITH DEFAULT ''
,lname VARCHAR(00015) NOT NULL WITH DEFAULT ''
,date_of_birth DATE
,citizenship CHAR(03)
,usa_sales USA_DOLLARS
,eur_sales EUR_DOLLARS
,sales_office# SMALLINT
,last_updated TIMESTAMP
,PRIMARY KEY(id));
Figure 46, Sample table, with distinct types
SELECT id
,usa_sales + eur_sales AS tot_sales
FROM customer;
Figure 47, Silly query, now fails
SELECT id
,DECIMAL(usa_sales) +
DECIMAL(eur_sales) AS tot_sales
FROM customer;
Figure 48, Silly query, works again
WITH
get_matching_rows AS
(
SELECT id
,name
,salary SUBSELECT
FROM staff
WHERE id < 50
UNION ALL FULLSELECT
SELECT id
,name
,salary SUBSELECT
FROM staff
WHERE id = 100
)
SELECT *
FROM get_matching_rows COMMON TABLE
ORDER BY id EXPRESSION
FETCH FIRST 10 ROWS ONLY SUBSELECT
FOR FETCH ONLY
WITH UR;
Figure 49, Query components
Figure 50, SELECT Statement Syntax (general)
Figure 51, SELECT Statement Syntax
SELECT deptno ANSWER
,admrdept ===================
,'ABC' AS abc DEPTNO ADMRDEPT ABC
FROM department ------ -------- ---
WHERE deptname LIKE '%ING%' B01 A00 ABC
ORDER BY 1; D11 D01 ABC
Figure 52, Sample SELECT statement
SELECT * ANSWER (part of)
FROM department ================
WHERE deptname LIKE '%ING%' DEPTNO etc...
ORDER BY 1; ------ ------>>>
B01 PLANNING
D11 MANUFACTU
Figure 53, Use "*" to select all columns in table
SELECT deptno ANSWER (part of)
,department.* =======================
FROM department DEPTNO DEPTNO etc...
WHERE deptname LIKE '%ING%' ------ ------ ------>>>
ORDER BY 1; B01 B01 PLANNING
D11 D11 MANUFACTU
Figure 54, Select an individual column, and all columns
SELECT department.* ANSWER (part of)
,department.* ================
FROM department DEPTNO etc...
WHERE deptname LIKE '%NING%' ------ ------>>>
ORDER BY 1; B01 PLANNING
Figure 55, Select all columns twice
Figure 56, Fetch First clause Syntax
SELECT years ANSWER
,name =====================
,id YEARS NAME ID
FROM staff ------ --------- ----
FETCH FIRST 3 ROWS ONLY; 7 Sanders 10
8 Pernal 20
5 Marenghi 30
Figure 57, FETCH FIRST without ORDER BY, gets random rows
SELECT years ANSWER
,name =====================
,id YEARS NAME ID
FROM staff ------ --------- ----
WHERE years IS NOT NULL 13 Graham 310
ORDER BY years DESC 12 Jones 260
FETCH FIRST 3 ROWS ONLY; 10 Hanes 50
Figure 58, FETCH FIRST with ORDER BY, gets wrong answer
SELECT years ANSWER
,name =====================
,id YEARS NAME ID
FROM staff ------ --------- ----
WHERE years IS NOT NULL 13 Graham 310
ORDER BY years DESC 12 Jones 260
,id DESC 10 Quill 290
FETCH FIRST 3 ROWS ONLY;
Figure 59, FETCH FIRST with ORDER BY, gets right answer
SELECT a.empno ANSWER
,a.lastname =================
FROM employee a EMPNO LASTNAME
,(SELECT MAX(empno)AS empno ------ ----------
FROM employee) AS b 000340 GOUNOT
WHERE a.empno = b.empno;
Figure 60, Correlation Name usage example
SELECT a.empno ANSWER
,a.lastname ======================
,b.deptno AS dept EMPNO LASTNAME DEPT
FROM employee a ------ ---------- ----
,department b 000090 HENDERSON E11
WHERE a.workdept = b.deptno 000280 SCHNEIDER E11
AND a.job <> 'SALESREP' 000290 PARKER E11
AND b.deptname = 'OPERATIONS' 000300 SMITH E11
AND a.sex IN ('M','F') 000310 SETRIGHT E11
AND b.location IS NULL
ORDER BY 1;
Figure 61, Correlation name usage example
SELECT empno AS e_num ANSWER
,midinit AS "m int" ===================
,phoneno AS "..." E_NUM M INT ...
FROM employee ------ ----- ----
WHERE empno < '000030' 000010 I 3978
ORDER BY 1; 000020 L 3476
Figure 62, Renaming fields using AS
CREATE view emp2 AS
SELECT empno AS e_num
,midinit AS "m int"
,phoneno AS "..."
FROM employee; ANSWER
===================
SELECT * E_NUM M INT ...
FROM emp2 ------ ----- ----
WHERE "..." = '3978'; 000010 I 3978
Figure 63, View field names defined using AS
SELECT AVG(comm) AS a1 ANSWER
,SUM(comm) / COUNT(*) AS a2 ===============
FROM staff A1 A2
WHERE id < 100; ------- ------
796.025 530.68
Figure 64, AVG of data containing null values
SELECT COUNT(*) AS num ANSWER
,MAX(lastname) AS max ========
FROM employee NUM MAX
WHERE firstnme = 'FRED'; --- ---
0 -
Figure 65, Getting a NULL value from a field defined NOT NULL
SELECT AVG(comm) AS a1 ANSWER
,SUM(comm) / COUNT(*) AS a2 ===============
FROM staff A1 A2
WHERE id < 100 ------- ------
AND comm IS NOT NULL; 796.025 796.02
Figure 66, AVG of those rows that are not null
SELECT 'JOHN' AS J1
,'JOHN''S' AS J2 ANSWER
,'''JOHN''S''' AS J3 =============================
,'"JOHN''S"' AS J4 J1 J2 J3 J4
FROM staff ---- ------ -------- --------
WHERE id = 10; JOHN JOHN'S 'JOHN'S' "JOHN'S"
Figure 67, Quote usage
SELECT id AS "USER ID" ANSWER
,dept AS "D#" ===============================
,years AS "#Y" USER ID D# #Y 'TXT' "quote" fld
,'ABC' AS "'TXT'" ------- -- -- ----- -----------
,'"' AS """quote"" fld" 10 20 7 ABC "
FROM staff s 20 20 8 ABC "
WHERE id < 40 30 38 5 ABC "
ORDER BY "USER ID";
Figure 68, Double-quote usage
Figure 69, Basic Predicate syntax, 1 of 2
SELECT id, job, dept ANSWER
FROM staff ===============
WHERE job = 'Mgr' ID JOB DEPT
AND NOT job <> 'Mgr' --- ---- ----
AND NOT job = 'Sales' 10 Mgr 20
AND id <> 100 30 Mgr 38
AND id >= 0 50 Mgr 15
AND id <= 150 140 Mgr 51
AND NOT dept = 50
ORDER BY id;
Figure 70, Basic Predicate examples
Figure 71, Basic Predicate syntax, 2 of 2
SELECT id, dept, job ANSWER
FROM staff ===========
WHERE (id,dept) = (30,28) ID DEPT JOB
OR (id,years) = (90, 7) -- ---- ---
OR (dept,job) = (38,'Mgr') 30 38 Mgr
ORDER BY 1;
Figure 72, Basic Predicate example, multi-value check
SELECT id, dept, job ANSWER
FROM staff ===========
WHERE (id = 30 AND dept = 28) ID DEPT JOB
OR (id = 90 AND years = 7) -- ---- ---
OR (dept = 38 AND job = 'Mgr') 30 38 Mgr
ORDER BY 1;
Figure 73, Same query as prior, using individual predicates
Figure 74, Quantified Predicate syntax
SELECT id, job ANSWER
FROM staff ========
WHERE job = ANY (SELECT job FROM staff) ID JOB
AND id <= ALL (SELECT id FROM staff) --- ----
ORDER BY id; 10 Mgr
Figure 75, Quantified Predicate example, two single-value sub-queries
SELECT id, dept, job ANSWER
FROM staff ==============
WHERE (id,dept) = ANY ID DEPT JOB
(SELECT dept, id --- ---- -----
FROM staff) 20 20 Sales
ORDER BY 1;
Figure 76, Quantified Predicate example, multi-value sub-query
Figure 77, BETWEEN Predicate syntax
SELECT id, job ANSWER
FROM staff =========
WHERE id BETWEEN 10 AND 30 ID JOB
AND id NOT BETWEEN 30 AND 10 --- -----
AND NOT id NOT BETWEEN 10 AND 30 10 Mgr
ORDER BY id; 20 Sales
30 Mgr
Figure 78, BETWEEN Predicate examples
Figure 79, EXISTS Predicate syntax
SELECT id, job ANSWER
FROM staff a =========
WHERE EXISTS ID JOB
(SELECT * --- -----
FROM staff b 10 Mgr
WHERE b.id = a.id 20 Sales
AND b.id < 50) 30 Mgr
ORDER BY id; 40 Sales
Figure 80, EXISTS Predicate example
Figure 81, IN Predicate syntax
SELECT id, job ANSWER
FROM staff a =========
WHERE id IN (10,20,30) ID JOB
AND id IN (SELECT id --- -----
FROM staff) 10 Mgr
AND id NOT IN 99 20 Sales
ORDER BY id; 30 Mgr
Figure 82, IN Predicate examples, single values
SELECT empno, lastname ANSWER
FROM employee ===============
WHERE (empno, 'AD3113') IN EMPNO LASTNAME
(SELECT empno, projno ------ -------
FROM emp_act 000260 JOHNSON
WHERE emptime > 0.5) 000270 PEREZ
ORDER BY 1;
Figure 83, IN Predicate example, multi-value
Figure 84, LIKE Predicate syntax
SELECT id, name ANSWER
FROM staff ==============
WHERE name LIKE 'S%n' ID NAME
OR name LIKE '_a_a%' --- ---------
OR name LIKE '%r_%a' 130 Yamaguchi
ORDER BY id; 200 Scoutten
Figure 85, LIKE Predicate examples
LIKE STATEMENT TEXT WHAT VALUES MATCH
=========================== ======================
LIKE 'AB%' Finds AB, any string
LIKE 'AB%' ESCAPE '+' Finds AB, any string
LIKE 'AB+%' ESCAPE '+' Finds AB%
LIKE 'AB++' ESCAPE '+' Finds AB+
LIKE 'AB+%%' ESCAPE '+' Finds AB%, any string
LIKE 'AB++%' ESCAPE '+' Finds AB+, any string
LIKE 'AB+++%' ESCAPE '+' Finds AB+%
LIKE 'AB+++%%' ESCAPE '+' Finds AB+%, any string
LIKE 'AB+%+%%' ESCAPE '+' Finds AB%%, any string
LIKE 'AB++++' ESCAPE '+' Finds AB++
LIKE 'AB+++++%' ESCAPE '+' Finds AB++%
LIKE 'AB++++%' ESCAPE '+' Finds AB++, any string
LIKE 'AB+%++%' ESCAPE '+' Finds AB%+, any string
Figure 86, LIKE and ESCAPE examples
SELECT id ANSWER
FROM staff ======
WHERE id = 10 ID
AND 'ABC' LIKE 'AB%' ---
AND 'A%C' LIKE 'A/%C' ESCAPE '/' 10
AND 'A_C' LIKE 'A\_C' ESCAPE '\'
AND 'A_$' LIKE 'A$_$$' ESCAPE '$';
Figure 87, LIKE and ESCAPE examples
Figure 88, NULL Predicate syntax
SELECT id, comm ANSWER
FROM staff =========
WHERE id < 100 ID COMM
AND id IS NOT NULL --- ----
AND comm IS NULL 10 -
AND NOT comm IS NOT NULL 30 -
ORDER BY id; 50 -
Figure 89, NULL predicate examples
SELECT id
,name
FROM staff
WHERE name LIKE '%a' || X'3B' || '%'
ORDER BY id;
Figure 90, Refer to semi-colon in SQL text
Example: 555 + -22 / (12 - 3) * 66 ANSWER
======
^ ^ ^ ^ ^ 423
5th 2nd 3rd 1st 4th
Figure 91, Precedence rules example
SELECT (12 - 3) AS int1
, -22 / (12 - 3) AS int2
, -22 / (12 - 3) * 66 AS int3
,555 + -22 / (12 - 3) * 66 AS int4
FROM sysibm.sysdummy1; ANSWER
===================
INT1 INT2 INT3 INT4
---- ---- ---- ----
9 -2 -132 423
Figure 92, Precedence rules, integer example
SELECT (12.0 - 3) AS dec1
, -22 / (12.0 - 3) AS dec2
, -22 / (12.0 - 3) * 66 AS dec3
,555 + -22 / (12.0 - 3) * 66 AS dec4
FROM sysibm.sysdummy1; ANSWER
===========================
DEC1 DEC2 DEC3 DEC4
------ ------ ------ ------
9.0 -2.4 -161.3 393.6
Figure 93, Precedence rules, decimal example
SELECT * ANSWER>> COL1 COL2 TABLE1
FROM table1 ---- ---- +---------+
WHERE col1 = 'C' A AA |COL1|COL2|
AND col1 >= 'A' B BB |----|----|
OR col2 >= 'AA' C CC |A |AA |
ORDER BY col1; |B |BB |
|C |CC |
SELECT * ANSWER>> COL1 COL2 +---------+
FROM table1 ---- ----
WHERE (col1 = 'C' A AA
AND col1 >= 'A') B BB
OR col2 >= 'AA' C CC
ORDER BY col1;
SELECT * ANSWER>> COL1 COL2
FROM table1 ---- ----
WHERE col1 = 'C' C CC
AND (col1 >= 'A'
OR col2 >= 'AA')
ORDER BY col1;
Figure 94, Use of OR and parenthesis
FROM clause
JOIN ON clause
WHERE clause
GROUP BY and aggregate
HAVING clause
SELECT list
ORDER BY clause
FETCH FIRST
Figure 95, Query Processing Sequence
Figure 96, CAST expression syntax
SELECT id ANSWER
,salary =================
,CAST(salary AS INTEGER) AS sal2 ID SALARY SAL2
FROM staff -- -------- -----
WHERE id < 30 10 98357.50 98357
ORDER BY id; 20 78171.25 78171
Figure 97, Use CAST expression to convert Decimal to Integer
SELECT id ANSWER
,job =============
,CAST(job AS CHAR(3)) AS job2 ID JOB JOB2
FROM staff -- ----- ----
WHERE id < 30 10 Mgr Mgr
ORDER BY id; 20 Sales Sal
Figure 98, Use CAST expression to truncate Char field
SELECT id ANSWER
,CAST(NULL AS SMALLINT) AS junk =======
FROM staff ID JUNK
WHERE id < 30 -- ----
ORDER BY id; 10 -
20 -
Figure 99, Use CAST expression to define SMALLINT field with null values
SELECT stf.id ANSWER
,emp.empno =========
FROM staff stf ID EMPNO
LEFT OUTER JOIN -- ------
employee emp 10 -
ON stf.id = CAST(emp.empno AS INTEGER) 20 000020
AND emp.job = 'MANAGER' 30 000030
WHERE stf.id < 60 40 -
ORDER BY stf.id; 50 000050
Figure 100, CAST expression in join
SELECT stf.id ANSWER
,emp.empno =========
FROM staff stf ID EMPNO
LEFT OUTER JOIN -- ------
employee emp 10 -
ON stf.id = INTEGER(emp.empno) 20 000020
AND emp.job = 'MANAGER' 30 000030
WHERE stf.id < 60 40 -
ORDER BY stf.id; 50 000050
Figure 101, Function usage in join
Figure 102, VALUES expression syntax
VALUES 6 <= 1 row, 1 column
VALUES (6) <= 1 row, 1 column
VALUES 6, 7, 8 <= 1 row, 3 columns
VALUES (6), (7), (8) <= 3 rows, 1 column
VALUES (6,66), (7,77), (8,NULL) <= 3 rows, 2 columns
Figure 103, VALUES usage examples
PLAIN VALUES VALUES + WITH VALUES + SELECT ANSWER
============ ==================== ================== ======
WITH temp (c1,c2) AS SELECT * 1 2
VALUES (1,2) (VALUES (1,2) FROM (VALUES (1,2) -- --
,(2,3) ,(2,3) ,(2,3) 3 4
,(3,4) ,(3,4)) ,(3,4) 2 3
ORDER BY 2 DESC; SELECT * )temp (c1,c2) 1 2
FROM temp ORDER BY 2 DESC;
ORDER BY 2 DESC;
Figure 104, Logically equivalent VALUES statements
VALUES ((SELECT COUNT(*) FROM employee) ANSWER
,(SELECT AVG(salary) FROM staff) ================
,(SELECT MAX(deptno) FROM department)) 1 2 3
FOR FETCH ONLY -- --------- ---
WITH UR; 42 67932.78 J22
Figure 105, VALUES running selects
WITH temp1 (col1, col2) AS ANSWER
(VALUES ( 0, 'AA') =========
,( 1, 'BB') COL1 COL2
,( 2, NULL) ---- ----
) 0 AA
SELECT * 1 BB
FROM temp1; 2 -
Figure 106, Use VALUES to define a temporary table (1 of 4)
WITH temp1 (col1, col2) AS ANSWER
(VALUES (DECIMAL(0 ,3,1), 'AA') =========
,(DECIMAL(1 ,3,1), 'BB') COL1 COL2
,(DECIMAL(2 ,3,1), NULL) ---- ----
) 0.0 AA
SELECT * 1.0 BB
FROM temp1; 2.0 -
Figure 107, Use VALUES to define a temporary table (2 of 4)
WITH temp1 (col1, col2) AS ANSWER
(VALUES ( 0, CAST('AA' AS CHAR(1))) =========
,( 1, CAST('BB' AS CHAR(1))) COL1 COL2
,( 2, CAST(NULL AS CHAR(1))) ---- ----
) 0 A
SELECT * 1 B
FROM temp1; 2 -
Figure 108, Use VALUES to define a temporary table (3 of 4)
WITH temp1 (col1, col2) AS ANSWER
(VALUES ( 0, CHAR('AA',1)) =========
,( 1, CHAR('BB',1)) COL1 COL2
,( 2, NULL) ---- ----
) 0 A
SELECT * 1 B
FROM temp1; 2 -
Figure 109, Use VALUES to define a temporary table (4 of 4)
WITH temp1 (col1, col2, col3) AS ANSWER
(VALUES ( 0, 'AA', 0.00) ==========
,( 1, 'BB', 1.11) COL1B COLX
,( 2, 'CC', 2.22) ----- ----
) 0 0.00
,temp2 (col1b, colx) AS 1 2.11
(SELECT col1 2 4.22
,col1 + col3
FROM temp1
)
SELECT *
FROM temp2;
Figure 110, Derive one temporary table from another
CREATE VIEW silly (c1, c2, c3)
AS VALUES (11, 'AAA', SMALLINT(22))
,(12, 'BBB', SMALLINT(33))
,(13, 'CCC', NULL);
COMMIT;
Figure 111, Define a view using a VALUES clause
WITH temp1 (col1) AS ANSWER
(VALUES 0 ======
UNION ALL COL1
SELECT col1 + 1 ----
FROM temp1 0
WHERE col1 + 1 < 100 1
) 2
SELECT * 3
FROM temp1; etc
Figure 112, Use VALUES defined data to seed a recursive SQL statement
SELECT * ANSWER
FROM (VALUES (123,'ABC') ======
,(234,'DEF') --- ---
)AS ttt 234 DEF
ORDER BY 1 DESC; 123 ABC
Figure 113, Generate table with unnamed columns
SELECT id ANSWER
,salary AS sal ===============================
,comm AS com ID SAL COM COMBO TYP
,combo -- -------- ------ -------- ---
,typ 10 98357.50 - - COM
FROM staff 10 98357.50 - 98357.50 SAL
,TABLE(VALUES(salary,'SAL') 20 78171.25 612.45 612.45 COM
,(comm, 'COM') 20 78171.25 612.45 78171.25 SAL
)AS tab(combo,typ) 30 77506.75 - - COM
WHERE id < 40 30 77506.75 - 77506.75 SAL
ORDER BY id
,typ;
Figure 114, Combine columns example
Figure 115, CASE expression syntax - 1st type
SELECT Lastname ANSWER
,sex AS sx ====================
,CASE sex LASTNAME SX SEXX
WHEN 'F' THEN 'FEMALE' ---------- -- ------
WHEN 'M' THEN 'MALE' JEFFERSON M MALE
ELSE NULL JOHN F FEMALE
END AS sexx JOHNSON F FEMALE
FROM employee JONES M MALE
WHERE lastname LIKE 'J%'
ORDER BY 1;
Figure 116, Use CASE (1st type) to expand a value
Figure 117, CASE expression syntax - 2nd type
SELECT lastname ANSWER
,sex AS sx ====================
,CASE LASTNAME SX SEXX
WHEN sex = 'F' THEN 'FEMALE' ---------- -- ------
WHEN sex = 'M' THEN 'MALE' JEFFERSON M MALE
ELSE NULL JOHN F FEMALE
END AS sexx JOHNSON F FEMALE
FROM employee JONES M MALE
WHERE lastname LIKE 'J%'
ORDER BY 1;
Figure 118, Use CASE (1st type) to expand a value
SELECT lastname ANSWER
,midinit AS mi ===================
,sex AS sx LASTNAME MI SX MX
,CASE ---------- -- -- --
WHEN midinit > SEX JEFFERSON J M M
THEN midinit JOHN K K K
ELSE sex JOHNSON P F P
END AS mx JONES T M T
FROM employee
WHERE lastname LIKE 'J%'
ORDER BY 1;
Figure 119, Use CASE to display the higher of two values
SELECT COUNT(*) AS tot ANSWER
,SUM(CASE sex WHEN 'F' THEN 1 ELSE 0 END) AS #f =========
,SUM(CASE sex WHEN 'M' THEN 1 ELSE 0 END) AS #m TOT #F #M
FROM employee --- -- --
WHERE lastname LIKE 'J%'; 4 2 2
Figure 120, Use CASE to get multiple counts in one pass
SELECT lastname ANSWER
,LENGTH(RTRIM(lastname)) AS len =====================
,SUBSTR(lastname,1, LASTNAME LEN LASTNM
CASE ---------- --- ------
WHEN LENGTH(RTRIM(lastname)) JEFFERSON 9 JEFFER
> 6 THEN 6 JOHN 4 JOHN
ELSE LENGTH(RTRIM(lastname)) JOHNSON 7 JOHNSO
END ) AS lastnm JONES 5 JONES
FROM employee
WHERE lastname LIKE 'J%'
ORDER BY 1;
Figure 121, Use CASE inside a function
UPDATE staff
SET comm = CASE dept
WHEN 15 THEN comm * 1.1
WHEN 20 THEN comm * 1.2
WHEN 38 THEN
CASE
WHEN years < 5 THEN comm * 1.3
WHEN years >= 5 THEN comm * 1.4
ELSE NULL
END
ELSE comm
END
WHERE comm IS NOT NULL
AND dept < 50;
Figure 122, UPDATE statement with nested CASE expressions
WITH temp1 (c1,c2) AS ANSWER
(VALUES (88,9),(44,3),(22,0),(0,1)) ========
SELECT c1 C1 C2 C3
,c2 -- -- --
,CASE c2 88 9 9
WHEN 0 THEN NULL 44 3 14
ELSE c1/c2 22 0 -
END AS c3 0 1 0
FROM temp1;
Figure 123, Use CASE to avoid divide by zero
SELECT lastname ANSWER
,sex =================
,CASE LASTNAME SX SXX
WHEN sex >= 'M' THEN 'MAL' ---------- -- ---
WHEN sex >= 'F' THEN 'FEM' JEFFERSON M MAL
END AS sxx JOHN F FEM
FROM employee JOHNSON F FEM
WHERE lastname LIKE 'J%' JONES M MAL
ORDER BY 1;
Figure 124, Use CASE to derive a value (correct)
SELECT lastname ANSWER
,sex =================
,CASE LASTNAME SX SXX
WHEN sex >= 'F' THEN 'FEM' ---------- -- ---
WHEN sex >= 'M' THEN 'MAL' JEFFERSON M FEM
END AS sxx JOHN F FEM
FROM employee JOHNSON F FEM
WHERE lastname LIKE 'J%' JONES M FEM
ORDER BY 1;
Figure 125, Use CASE to derive a value (incorrect)
SELECT id ANSWER
,dept =======================
,salary ID DEPT SALARY COMM
,comm --- ---- -------- -----
FROM staff 130 42 10505.90 75.60
WHERE CASE 270 66 18555.50 -
WHEN comm < 70 THEN 'A' 330 66 10988.00 55.50
WHEN name LIKE 'W%' THEN 'B'
WHEN salary < 11000 THEN 'C'
WHEN salary < 18500
AND dept <> 33 THEN 'D'
WHEN salary < 19000 THEN 'E'
END IN ('A','C','E')
ORDER BY id;
Figure 126, Use CASE in a predicate
ANSWER
=======================
ID DEPT SALARY COMM
SELECT id --- ---- -------- -----
,name 130 42 10505.90 75.60
,salary 270 66 18555.50 -
,comm 330 66 10988.00 55.50
FROM staff
WHERE (comm < 70)
OR (salary < 11000 AND NOT name LIKE 'W%')
OR (salary < 19000 AND NOT (name LIKE 'W%'
OR (salary < 18500 AND dept <> 33)))
ORDER BY id;
Figure 127, Same stmt as prior, without CASE predicate
Figure 128, DECLARE CURSOR statement syntax
DECLARE fred CURSOR FOR
WITH RETURN TO CALLER
SELECT id
,name
,salary
,comm
FROM staff
WHERE id < :id-var
AND salary > 1000
ORDER BY id ASC
FETCH FIRST 10 ROWS ONLY
OPTIMIZE FOR 10 ROWS
FOR FETCH ONLY
WITH UR
Figure 129, Sample cursor
DECLARE fred CURSOR WITH HOLD FOR
SELECT name
,salary
FROM staff
WHERE id > :id-var
FOR UPDDATE OF salary, comm
OPEN fred
DO UNTIL SQLCODE = 100
FETCH fred
INTO :name-var
,:salary-var
IF salary < 1000 THEN DO
UPDATE staff
SET salary = :new-salary-var
WHERE CURRENT OF fred
END-IF
END-DO
CLOSE fred
Figure 130, Use cursor in program
SELECT name
,salary
INTO :name-var
,:salary-var
FROM staff
WHERE id = :id-var
Figure 131, Singleton select
Figure 132, PREPARE statement syntax
STATEMENT CAN BE USED BY STATEMENT TYPE
======================== ==============
DESCRIBE Any statement
DECLARE CURSOR Must be SELECT
EXECUTE Must not be SELECT
Figure 133, What statements can use prepared statement
Figure 134, DESCRIBE statement syntax
DESCRIBE OUTPUT SELECT * FROM staff
SQLDA Information
sqldaid : SQLDA sqldabc: 896 sqln: 20 sqld: 7
Column Information
sqltype sqllen sqlname.data sqlname.length
------------------ ------ -------------------------- --------------
500 SMALLINT 2 ID 2
449 VARCHAR 9 NAME 4
501 SMALLINT 2 DEPT 4
453 CHARACTER 5 JOB 3
501 SMALLINT 2 YEARS 5
485 DECIMAL 7, 2 SALARY 6
485 DECIMAL 7, 2 COMM 4
Figure 135, DESCRIBE the output columns in a select statement
DESCRIBE TABLE staff
Column Type Type
name schema name Length Scale Nulls
----------------------- -------- ------------ ------- ----- -----
ID SYSIBM SMALLINT 2 0 No
NAME SYSIBM VARCHAR 9 0 Yes
DEPT SYSIBM SMALLINT 2 0 Yes
JOB SYSIBM CHARACTER 5 0 Yes
YEARS SYSIBM SMALLINT 2 0 Yes
SALARY SYSIBM DECIMAL 7 2 Yes
COMM SYSIBM DECIMAL 7 2 Yes
Figure 136, DESCRIBE the columns in a table
SET :host-var = CURRENT TIMESTAMP
Figure 137, SET single host-variable
SET :host-v1 = CURRENT TIME
,:host-v2 = CURRENT DEGREE
,:host-v3 = NULL
Figure 138, SET multiple host-variables
SET (:hv1
,:hv2
,:hv3) =
(SELECT id
,name
,salary
FROM staff
WHERE id = :id-var)
Figure 139, SET using row-fullselect
SET CONNECTION
SET CURRENT DEFAULT TRANSFORM GROUP
SET CURRENT DEGREE
SET CURRENT EXPLAIN MODE
SET CURRENT EXPLAIN SNAPSHOT
SET CURRENT ISOLATION
SET CURRENT LOCK TIMEOUT
SET CURRENT MAINTAINED TABLE TYPES FOR OPTIMIZATION
SET CURRENT PACKAGE PATH
SET CURRENT PACKAGESET
SET CURRENT QUERY OPTIMIZATION
SET CURRENT REFRESH AGE
SET ENCRYPTION PASSWORD
SET EVENT MONITOR STATE
SET INTEGRITY
SET PASSTHRU
SET PATH
SET SCHEMA
SET SERVER OPTION
SET SESSION AUTHORIZATION
Figure 140, Other SET statements
Figure 141, SAVEPOINT statement syntax
Figure 142, Example of savepoint usage
Figure 143, RELEASE SAVEPOINT statement syntax
Figure 144, ROLLBACK statement syntax
CREATE TABLE emp_act_copy
(empno CHARACTER (00006) NOT NULL
,projno CHARACTER (00006) NOT NULL
,actno SMALLINT NOT NULL
,emptime DECIMAL (05,02)
,emstdate DATE
,emendate DATE);
Figure 145, EMP_ACT_COPY sample table - DDL
Figure 146, INSERT statement syntax
INSERT INTO emp_act_copy VALUES
('100000' ,'ABC' ,10 ,1.4 ,'2003-10-22', '2003-11-24');
Figure 147, Single row insert
INSERT INTO emp_act_copy VALUES
('200000' ,'ABC' ,10 ,1.4 ,'2003-10-22', '2003-11-24')
,('200000' ,'DEF' ,10 ,1.4 ,'2003-10-22', '2003-11-24')
,('200000' ,'IJK' ,10 ,1.4 ,'2003-10-22', '2003-11-24');
Figure 148, Multi row insert
INSERT INTO emp_act_copy VALUES
('400000' ,'ABC' ,10 ,NULL ,DEFAULT, CURRENT DATE);
Figure 149,Using null and default values
INSERT INTO emp_act_copy (projno, emendate, actno, empno) VALUES
('ABC' ,DATE(CURRENT TIMESTAMP) ,123 ,'500000');
Figure 150, Explicitly listing columns being populated during insert
INSERT INTO
(SELECT *
FROM emp_act_copy
WHERE empno < '1'
)
VALUES ('510000' ,'ABC' ,10 ,1.4 ,'2003-10-22', '2003-11-24');
Figure 151, Insert into a fullselect
INSERT INTO emp_act_copy
SELECT LTRIM(CHAR(id + 600000))
,SUBSTR(UCASE(name),1,6)
,salary / 229
,123
,CURRENT DATE
,'2003-11-11'
FROM staff
WHERE id < 50;
Figure 152,Insert result of select statement
INSERT INTO emp_act_copy (empno, actno, projno)
SELECT LTRIM(CHAR(id + 700000))
,MINUTE(CURRENT TIME)
,'DEF'
FROM staff
WHERE id < 40;
Figure 153, Insert result of select - specified columns only
INSERT INTO emp_act_copy
SELECT * FROM emp_act_copy;
Figure 154, Stupid - insert - doubles rows
INSERT INTO emp_act_copy (empno, actno, projno)
SELECT LTRIM(CHAR(id + 800000))
,77
,'XYZ'
FROM staff
WHERE id < 40
UNION
SELECT LTRIM(CHAR(id + 900000))
,SALARY / 100
,'DEF'
FROM staff
WHERE id < 50;
Figure 155, Inserting result of union
INSERT INTO emp_act_copy (empno, actno, projno, emptime)
WITH temp1 (col1) AS
(VALUES (1),(2),(3),(4),(5),(6))
SELECT LTRIM(CHAR(col1 + 910000))
,col1
,CHAR(col1)
,col1 / 2
FROM temp1;
Figure 156, Insert from common table expression
INSERT INTO emp_act_copy (empno, actno, projno)
SELECT LTRIM(CHAR(id + 920000))
,id
,'ABC'
FROM staff
WHERE id < 40
AND NOT EXISTS
(SELECT *
FROM emp_act_copy
WHERE empno LIKE '92%');
Figure 157, Insert with irrelevant sub-query
CREATE TABLE us_customer CREATE TABLE intl_customer
(cust# INTEGER NOT NULL (cust# INTEGER NOT NULL
,cname CHAR(10) NOT NULL ,cname CHAR(10) NOT NULL
,country CHAR(03) NOT NULL ,country CHAR(03) NOT NULL
,CHECK (country = 'USA') ,CHECK (country <> 'USA')
,PRIMARY KEY (cust#)); ,PRIMARY KEY (cust#));
Figure 158, Customer tables - for insert usage
INSERT INTO
(SELECT *
FROM us_customer
UNION ALL
SELECT *
FROM intl_customer)
VALUES (111,'Fred','USA')
,(222,'Dave','USA')
,(333,'Juan','MEX');
Figure 159, Insert into multiple tables
UPDATE emp_act_copy
SET emptime = NULL
,emendate = DEFAULT
,emstdate = CURRENT DATE + 2 DAYS
,actno = ACTNO / 2
,projno = 'ABC'
WHERE empno = '100000';
Figure 160, Single row update
Figure 161, UPDATE statement syntax
UPDATE emp_act_copy
SET actno = actno / 2;
Figure 162, Mass update
UPDATE emp_act_copy ac1
SET actno = actno * 2
,emptime = actno * 2
WHERE empno LIKE '910%';
Figure 163, Two columns get same value
UPDATE emp_act_copy
SET actno = (SELECT MAX(salary) / 10
FROM staff)
WHERE empno = '200000';
Figure 164, Update using select
UPDATE emp_act_copy
SET (actno
,emstdate
,projno) = (SELECT MAX(salary) / 10
,CURRENT DATE + 2 DAYS
,MIN(CHAR(id))
FROM staff
WHERE id <> 33)
WHERE empno LIKE '600%';
Figure 165, Multi-row update using select
UPDATE emp_act_copy ac1
SET (actno
,emptime) = (SELECT ac2.actno + 1
,ac1.emptime / 2
FROM emp_act_copy ac2
WHERE ac2.empno LIKE '60%'
AND SUBSTR(ac2.empno,3) = SUBSTR(ac1.empno,3))
WHERE EMPNO LIKE '700%';
Figure 166, Multi-row update using correlated select
UPDATE emp_act_copy
SET emptime = 10
WHERE empno = '000010'
AND projno = 'MA2100';
Figure 167, Direct update of table
UPDATE
(SELECT *
FROM emp_act_copy
WHERE empno = '000010'
AND projno = 'MA2100'
)AS ea
SET emptime = 20;
Figure 168, Update of fullselect
UPDATE
(SELECT *
FROM staff
ORDER BY salary DESC
FETCH FIRST 5 ROWS ONLY
)AS xxx
SET comm = 10000;
Figure 169, Update first "n" rows
UPDATE emp_act_copy ea1
SET emptime = (SELECT MAX(emptime)
FROM emp_act_copy ea2
WHERE ea1.empno = ea2.empno)
WHERE empno = '000010'
AND projno = 'MA2100';
Figure 170, Set employee-time in row to MAX - for given employee
UPDATE
(SELECT ea1.*
,MAX(emptime) OVER(PARTITION BY empno) AS maxtime
FROM emp_act_copy ea1
)AS ea2
SET emptime = maxtime
WHERE empno = '000010'
AND projno = 'MA2100';
Figure 171, Use OLAP function to get max-time, then apply (correct)
UPDATE emp_act_copy
SET emptime = MAX(emptime) OVER(PARTITION BY empno)
WHERE empno = '000010'
AND projno = 'MA2100';
Figure 172, Use OLAP function to get max-time, then apply (wrong)
UPDATE emp_act_copy ac1
SET (actno
,emptime) = (SELECT ROW_NUMBER() OVER()
,ac1.emptime / 2
FROM emp_act_copy ac2
WHERE ac2.empno LIKE '60%'
AND SUBSTR(ac2.empno,3) = SUBSTR(ac1.empno,3))
WHERE EMPNO LIKE '800%';
Figure 173, Update with correlated query
UPDATE emp_act_copy ac1
SET (actno
,emptime) = (SELECT c1
,c2
FROM (SELECT ROW_NUMBER() OVER() AS c1
,actno / 100 AS c2
,empno
FROM emp_act_copy
WHERE empno LIKE '60%'
)AS ac2
WHERE SUBSTR(ac2.empno,3) = SUBSTR(ac1.empno,3))
WHERE empno LIKE '900%';
Figure 174, Update with uncorrelated query
DELETE
FROM emp_act_copy
WHERE empno = '000010'
AND projno = 'MA2100'
AND actno = 10;
Figure 175, Single-row delete
Figure 176, DELETE statement syntax
DELETE
FROM emp_act_copy;
Figure 177, Mass delete
DELETE
FROM emp_act_copy
WHERE empno LIKE '00%'
AND projno >= 'MA';
Figure 178, Selective delete
DELETE
FROM staff s1
WHERE id NOT IN
(SELECT MAX(id)
FROM staff s2
WHERE s1.dept = s2.dept);
Figure 179, Correlated delete (1 of 2)
DELETE
FROM staff s1
WHERE EXISTS
(SELECT *
FROM staff s2
WHERE s2.dept = s1.dept
AND s2.id > s1.id);
Figure 180, Correlated delete (2 of 2)
DELETE FROM
(SELECT id
,MAX(id) OVER(PARTITION BY dept) AS max_id
FROM staff
)AS ss
WHERE id <> max_id;
Figure 181, Delete using fullselect and OLAP function
DELETE
FROM (SELECT *
FROM staff
ORDER BY salary DESC
FETCH FIRST 5 ROWS ONLY
)AS xxx;
Figure 182, Delete first "n" rows
Figure 183, Select DML statement syntax
ANSWER
==============
SELECT empno EMPNO PRJ ACT
,projno AS prj ------ --- ---
,actno AS act 200000 ABC 10
FROM FINAL TABLE 200000 DEF 10
(INSERT INTO emp_act_copy
VALUES ('200000','ABC',10 ,1,'2003-10-22','2003-11-24')
,('200000','DEF',10 ,1,'2003-10-22','2003-11-24'))
ORDER BY 1,2,3;
Figure 184, Select rows inserted
SELECT empno ANSWER
,projno AS prj =================
,actno AS act EMPNO PRJ ACT R#
,row# AS r# ------ --- --- --
FROM FINAL TABLE 300000 ZZZ 999 1
(INSERT INTO emp_act_copy (empno, projno, actno) 300000 VVV 111 2
INCLUDE (row# SMALLINT)
VALUES ('300000','ZZZ',999,1)
,('300000','VVV',111,2))
ORDER BY row#;
Figure 185, Include column to get insert sequence
SELECT empno ANSWER
,projno AS prj =================
,actno AS act EMPNO PRJ ACT R#
,ROW_NUMBER() OVER() AS r# ------ --- --- --
FROM FINAL TABLE 400000 ZZZ 999 1
(INSERT INTO emp_act_copy (empno, projno, actno) 400000 VVV 111 2
VALUES ('400000','ZZZ',999)
,('400000','VVV',111))
ORDER BY INPUT SEQUENCE;
Figure 186, Select rows in insert order
SELECT empno ANSWER
,projno AS prj =================
,actno AS act EMPNO PRJ ACT R#
,ROW_NUMBER() OVER() AS r# ------ --- -- --
FROM NEW TABLE 600010 1 59 1
(INSERT INTO emp_act_copy (empno, actno, projno) 600020 563 59 2
SELECT LTRIM(CHAR(id + 600000)) 600030 193 59 3
,SECOND(CURRENT TIME)
,CHAR(SMALLINT(RAND(1) * 1000))
FROM staff
WHERE id < 40)
ORDER BY INPUT SEQUENCE;
Figure 187, Select from an insert that has unknown values
SELECT empno ANSWER
,projno AS prj ================
,emptime AS etime EMPNO PRJ ETIME
FROM OLD TABLE ------ --- -----
(UPDATE emp_act_copy 200000 ABC 1.00
SET emptime = emptime * 2 200000 DEF 1.00
WHERE empno = '200000')
ORDER BY projno;
Figure 188, Select values - from before update
SELECT projno AS prj ANSWER
,old_t AS old_t ===============
,emptime AS new_t PRJ OLD_T NEW_T
FROM NEW TABLE --- ----- -----
(UPDATE emp_act_copy ABC 2.00 0.02
INCLUDE (old_t DECIMAL(5,2)) DEF 2.00 11.27
SET emptime = emptime * RAND(1) * 10
,old_t = emptime
WHERE empno = '200000')
ORDER BY 1;
Figure 189, Select values - before and after update
SELECT projno AS prj ANSWER
,actno AS act =======
FROM OLD TABLE PRJ ACT
(DELETE --- ---
FROM emp_act_copy VVV 111
WHERE empno = '300000') ZZZ 999
ORDER BY 1,2;
Figure 190, List deleted rows
SELECT empno ANSWER
,projno ====================
,actno AS act EMPNO PROJNO ACT R#
,row# AS r# ------ ------ --- --
FROM OLD TABLE 000260 AD3113 70 2
(DELETE 000260 AD3113 80 4
FROM emp_act_copy 000260 AD3113 180 6
INCLUDE (row# SMALLINT)
SET row# = ROW_NUMBER() OVER()
WHERE empno = '000260')
WHERE row# = row# / 2 * 2
ORDER BY 1,2,3;
Figure 191, Assign row numbers to deleted rows
SELECT empno ANSWER
,(SELECT lastname ==========================
FROM (SELECT empno AS e# EMPNO LASTNAME PROJNO ACT
,lastname ------ -------- ------ ---
FROM employee 000010 HAAS AD3100 10
)AS xxx 000010 HAAS MA2100 10
WHERE empno = e#) 000010 HAAS MA2110 10
,projno AS projno 000020 THOMPSON PL2100 30
,actno AS act 000030 KWAN IF1000 10
FROM OLD TABLE
(DELETE
FROM emp_act_copy
WHERE empno < '0001')
ORDER BY 1,2,3
FETCH FIRST 5 ROWS ONLY;
Figure 192, Join result to another table
Figure 193, MERGE statement syntax
CREATE TABLE old_staff AS OLD_STAFF NEW_STAFF
(SELECT id, job, salary +-----------------+ +----------+
FROM staff) |ID|JOB |SALARY | |ID|SALARY |
WITH NO DATA; |--|-----|--------| |--|-------|
|20|Sales|78171.25| |30|7750.67|
CREATE TABLE new_staff AS |30|Mgr |77506.75| |40|7800.60|
(SELECT id, salary |40|Sales|78006.00| |50|8065.98|
FROM staff) +-----------------+ +----------+
WITH NO DATA;
INSERT INTO old_staff INSERT INTO new_staff
SELECT id, job, salary SELECT id, salary / 10
FROM staff FROM staff
WHERE id BETWEEN 20 and 40; WHERE id BETWEEN 30 and 50;
Figure 194, Sample tables for merge
MERGE INTO old_staff oo OLD_STAFF NEW_STAFF
USING new_staff nn +-----------------+ +----------+
ON oo.id = nn.id |ID|JOB |SALARY | |ID|SALARY |
WHEN MATCHED THEN |--|-----|--------| |--|-------|
UPDATE |20|Sales|78171.25| |30|7750.67|
SET oo.salary = nn.salary |30|Mgr |77506.75| |40|7800.60|
WHEN NOT MATCHED THEN |40|Sales|78006.00| |50|8065.98|
INSERT +-----------------+ +----------+
VALUES (nn.id,'?',nn.salary);
AFTER-MERGE
=================
ID JOB SALARY
-- ----- --------
20 Sales 78171.25
30 Mgr 7750.67
40 Sales 7800.60
50 ? 8065.98
Figure 195, Merge - do update or insert
MERGE INTO old_staff oo AFTER-MERGE
USING new_staff nn =================
ON oo.id = nn.id ID JOB SALARY
WHEN MATCHED THEN -- ----- --------
DELETE; 20 Sales 78171.25
Figure 196, Merge - delete if match
MERGE INTO old_staff oo OLD_STAFF NEW_STAFF
USING new_staff nn +-----------------+ +----------+
ON oo.id = nn.id |ID|JOB |SALARY | |ID|SALARY |
WHEN MATCHED |--|-----|--------| |--|-------|
AND oo.salary < 78000 THEN |20|Sales|78171.25| |30|7750.67|
UPDATE |30|Mgr |77506.75| |40|7800.60|
SET oo.salary = nn.salary |40|Sales|78006.00| |50|8065.98|
WHEN MATCHED +-----------------+ +----------+
AND oo.salary > 78000 THEN
DELETE AFTER-MERGE
WHEN NOT MATCHED =================
AND nn.id > 10 THEN ID JOB SALARY
INSERT -- ----- --------
VALUES (nn.id,'?',nn.salary) 20 Sales 78171.25
WHEN NOT MATCHED THEN 30 Mgr 7750.67
SIGNAL SQLSTATE '70001' 50 ? 8065.98
SET MESSAGE_TEXT = 'New ID <= 10';
Figure 197, Merge with multiple options
MERGE INTO old_staff AFTER-MERGE
USING =================
(SELECT MAX(id) + 1 AS max_id ID JOB SALARY
,MAX(job) AS max_job -- ----- --------
,MAX(salary) AS max_sal 20 Sales 78171.25
FROM old_staff 30 Mgr 77506.75
)AS mx 40 Sales 78006.00
ON id = max_id 41 Sales 78171.25
WHEN NOT MATCHED THEN
INSERT
VALUES (max_id, max_job, max_sal);
Figure 198, Merge MAX row into table
INSERT INTO old_staff
SELECT MAX(id) + 1 AS max_id
,MAX(job) AS max_job
,MAX(salary) AS max_sal
FROM old_staff;
Figure 199, Merge logic - done using insert
MERGE INTO OLD_STAFF NEW_STAFF
(SELECT * +-----------------+ +----------+
FROM old_staff |ID|JOB |SALARY | |ID|SALARY |
WHERE id < 40 |--|-----|--------| |--|-------|
)AS oo |20|Sales|78171.25| |30|7750.67|
USING |30|Mgr |77506.75| |40|7800.60|
(SELECT * |40|Sales|78006.00| |50|8065.98|
FROM new_staff +-----------------+ +----------+
WHERE id < 50
)AS nn AFTER-MERGE
ON oo.id = nn.id =================
WHEN MATCHED THEN ID JOB SALARY
DELETE -- ----- --------
WHEN NOT MATCHED THEN 20 Sales 78171.25
INSERT 40 ? 7800.60
VALUES (nn.id,'?',nn.salary); 40 Sales 78006.00
Figure 200, Merge using two fullselects
MERGE INTO old_staff oo AFTER-MERGE
USING new_staff nn =================
ON oo.id = nn.id ID JOB SALARY
WHEN MATCHED THEN -- ----- --------
UPDATE 20 Sales 78171.25
SET (salary,job) = (1234,'?') 30 ? 1234.00
WHEN NOT MATCHED THEN 40 ? 1234.00
INSERT (id,salary,job) 50 ? 5678.90
VALUES (id,5678.9,'?');
Figure 201, Listing columns and values in insert
Figure 202, Compound SQL Statement syntax
BEGIN ATOMIC
DECLARE cntr SMALLINT DEFAULT 1;
FOR V1 AS
SELECT id as idval
FROM staff
WHERE id < 80
ORDER BY id
DO
UPDATE staff
SET comm = cntr
WHERE id = idval;
SET cntr = cntr + 1;
END FOR;
END
Figure 203, Sample Compound SQL statement
--#SET DELIMITER !
SELECT NAME FROM STAFF WHERE id = 10!
--#SET DELIMITER ;
SELECT NAME FROM STAFF WHERE id = 20;
Figure 204, Set Delimiter example
BEGIN ATOMIC
DECLARE aaa, bbb, ccc SMALLINT DEFAULT 1;
DECLARE ddd CHAR(10) DEFAULT NULL;
DECLARE eee INTEGER;
SET eee = aaa + 1;
UPDATE staff
SET comm = aaa
,salary = bbb
,years = eee
WHERE id = 10;
END
Figure 205, DECLARE examples
Figure 206, FOR statement syntax
BEGIN ATOMIC BEFORE
FOR V1 AS ====================
SELECT years AS yr_num ID SALARY COMM
,max(id) AS max_id --- --------- ------
FROM staff 180 37009.75 236.50
WHERE years < 4 230 83369.80 189.65
GROUP BY years 330 49988.00 55.50
ORDER BY years
DO
UPDATE staff AFTER
SET salary = salary / 10 ====================
WHERE id = max_id; ID SALARY COMM
UPDATE staff --- --------- ------
set comm = 0 180 37009.75 0.00
WHERE years = yr_num; 230 8336.98 0.00
END FOR; 330 4998.80 0.00
END
Figure 207, FOR statement example
Figure 208, GET DIAGNOSTICS statement syntax
BEGIN ATOMIC
DECLARE numrows INT DEFAULT 0;
UPDATE staff
SET salary = 12345
WHERE id < 100;
GET DIAGNOSTICS numrows = ROW_COUNT;
UPDATE staff
SET salary = numrows
WHERE id = 10;
END
Figure 209, GET DIAGNOSTICS statement example
Figure 210, IF statement syntax
BEGIN ATOMIC
DECLARE cur INT;
SET cur = MICROSECOND(CURRENT TIMESTAMP);
IF cur > 600000 THEN
UPDATE staff
SET name = CHAR(cur)
WHERE id = 10;
ELSEIF cur > 300000 THEN
UPDATE staff
SET name = CHAR(cur)
WHERE id = 20;
ELSE
UPDATE staff
SET name = CHAR(cur)
WHERE id = 30;
END IF;
END
Figure 211, IF statement example
Figure 212, ITERATE statement syntax
BEGIN ATOMIC
DECLARE cntr INT DEFAULT 0;
whileloop:
WHILE cntr < 60 DO
SET cntr = cntr + 10;
UPDATE staff
SET salary = cntr
WHERE id = cntr;
ITERATE whileloop;
UPDATE staff
SET comm = cntr + 1
WHERE id = cntr;
END WHILE;
END
Figure 213, ITERATE statement example
Figure 214, LEAVE statement syntax
BEGIN ATOMIC
DECLARE cntr INT DEFAULT 1;
whileloop:
WHILE 1 <> 2 DO
SET cntr = cntr + 1;
IF RAND() > 0.99 THEN
LEAVE whileloop;
END IF;
END WHILE;
UPDATE staff
SET salary = cntr
WHERE id = 10;
END
Figure 215, LEAVE statement example
Figure 216, SIGNAL statement syntax
BEGIN ATOMIC
DECLARE cntr INT DEFAULT 1;
DECLARE emsg CHAR(20);
whileloop:
WHILE RAND() < .99 DO
SET cntr = cntr + 1;
END WHILE;
SET emsg = '#loops: ' || CHAR(cntr);
SIGNAL SQLSTATE '75001' SET MESSAGE_TEXT = emsg;
END
Figure 217, SIGNAL statement example
Figure 218, WHILE statement syntax
BEGIN ATOMIC
DECLARE c1, C2 INT DEFAULT 1;
WHILE c1 < 10 DO
WHILE c2 < 20 DO
SET c2 = c2 + 1;
END WHILE;
SET c1 = c1 + 1;
END WHILE;
UPDATE staff
SET salary = c1
,comm = c2
WHERE id = 10;
END
Figure 219, WHILE statement example
SELECT dept ANSWER
,count(*) as #rows ==========
FROM staff DEPT #ROWS
GROUP BY dept ---- -----
ORDER BY dept; 10 4
15 4
20 4
38 5
42 4
51 5
66 5
84 4
Figure 220, List departments in STAFF table
--#SET DELIMITER ! IMPORTANT
============
CREATE TABLE dpt This example
(dept SMALLINT NOT NULL uses an "!"
,#names SMALLINT as the stmt
,PRIMARY KEY(dept))! delimiter.
COMMIT!
CREATE TRIGGER dpt1 AFTER INSERT ON dpt
REFERENCING NEW AS NNN
FOR EACH ROW
MODE DB2SQL
BEGIN ATOMIC
DECLARE namecnt SMALLINT DEFAULT 0;
FOR getnames AS
SELECT COUNT(*) AS #n
FROM staff
WHERE dept = nnn.dept
DO
SET namecnt = #n;
END FOR;
UPDATE dpt
SET #names = namecnt
WHERE dept = nnn.dept; ANSWER
END! ===========
COMMIT! DEPT #NAMES
---- ------
INSERT INTO dpt (dept) 10 4
SELECT DISTINCT dept 15 4
FROM staff! 20 4
COMMIT! 38 5
42 4
SELECT * 51 5
FROM dpt 66 5
ORDER BY dept! 84 4
Figure 221, Trigger with compound SQL
--#SET DELIMITER ! IMPORTANT
============
CREATE FUNCTION dpt1 (deptin SMALLINT) This example
RETURNS SMALLINT uses an "!"
BEGIN ATOMIC as the stmt
DECLARE num_names SMALLINT; delimiter.
FOR getnames AS
SELECT COUNT(*) AS #n
FROM staff
WHERE dept = deptin
DO
SET num_names = #n;
END FOR; ANSWER
RETURN num_names; ===========
END! DEPT #NAMES
COMMIT! ---- ------
10 4
SELECT XXX.* 15 4
,dpt1(dept) as #names 20 4
FROM (SELECT dept 38 5
FROM staff 42 4
GROUP BY dept 51 5
)AS XXX 66 5
ORDER BY dept! 84 4
Figure 222, Scalar Function with compound SQL
--#SET DELIMITER ! IMPORTANT
============
CREATE FUNCTION dpt1 (deptin SMALLINT) This example
RETURNS SMALLINT uses an "!"
BEGIN ATOMIC as the stmt
RETURN delimiter.
SELECT COUNT(*)
FROM staff
WHERE dept = deptin;
END!
COMMIT!
SELECT XXX.*
,dpt1(dept) as #names
FROM (SELECT dept
FROM staff
GROUP BY dept
)AS XXX
ORDER BY dept!
Figure 223, Scalar Function with compound SQL
--#SET DELIMITER ! IMPORTANT
============
CREATE FUNCTION dpt2 () This example
RETURNS TABLE (dept SMALLINT uses an "!"
,#names SMALLINT) as the stmt
BEGIN ATOMIC delimiter.
RETURN
SELECT dept
,count(*) ANSWER
FROM staff ===========
GROUP BY dept DEPT #NAMES
ORDER BY dept; ---- ------
END! 10 4
COMMIT! 15 4
20 4
--#SET DELIMITER ; 38 5
42 4
SELECT * 51 5
FROM TABLE(dpt2()) T1 66 5
ORDER BY dept; 84 4
Figure 224, Table Function with compound SQL
Figure 225, ARRAY_AGG function syntax
Figure 226, AVG function syntax
SELECT AVG(dept) AS a1 ANSWER
,AVG(ALL dept) AS a2 ==============
,AVG(DISTINCT dept) AS a3 A1 A2 A3 A4 A5
,AVG(dept/10) AS a4 -- -- -- -- --
,AVG(dept)/10 AS a5 41 41 40 3 4
FROM staff
HAVING AVG(dept) > 40;
Figure 227, AVG function examples
UPDATE staff
SET comm = 0
WHERE comm IS NULL;
SELECT AVG(salary) AS salary ANSWER
,AVG(comm) AS comm1 ======================
,AVG(CASE comm SALARY COMM1 COMM2
WHEN 0 THEN NULL -------- ------ ------
ELSE comm 67932.78 351.98 513.31
END) AS comm2
FROM staff;
UPDATE staff
SET comm = NULL
WHERE comm = 0;
Figure 228, Convert zero to null before doing AVG
SELECT COUNT(*) AS c1 ANSWER
,AVG(salary) AS a1 ===========
,COALESCE(AVG(salary),0) AS a2 C1 A1 A2 A3
,CASE -- -- -- --
WHEN AVG(salary) IS NULL THEN 0 0 - 0 0
ELSE AVG(salary)
END AS a3
FROM staff
WHERE id < 10;
Figure 229, Convert null output (from AVG) to zero
SELECT AVG(DAYS(birthdate)) ANSWER
,DATE(AVG(DAYS(birthdate))) =================
FROM employee; 1 2
------ ----------
721092 1975-04-14
Figure 230, AVG of date column
SELECT AVG(avg_sal) AS avg_avg ANSWER
FROM (SELECT dept ================
,AVG(salary) AS avg_sal
FROM staff
GROUP BY dept
)AS xxx;
Figure 231, Select average of average
Figure 232, CORRELATION function syntax
WITH temp1(col1, col2, col3, col4) AS ANSWER
(VALUES (0 , 0 , 0 , RAND(1)) ===========================
UNION ALL COR11 COR12 COR23 COR34
SELECT col1 + 1 ------ ------ ------ ------
,col2 - 1 1.000 -1.000 -0.017 -0.005
,RAND()
,RAND()
FROM temp1
WHERE col1 <= 1000
)
SELECT DEC(CORRELATION(col1,col1),5,3) AS cor11
,DEC(CORRELATION(col1,col2),5,3) AS cor12
,DEC(CORRELATION(col2,col3),5,3) AS cor23
,DEC(CORRELATION(col3,col4),5,3) AS cor34
FROM temp1;
Figure 233, CORRELATION function examples
Figure 234, COUNT function syntax
SELECT COUNT(*) AS c1 ANSWER
,COUNT(INT(comm/10)) AS c2 =================
,COUNT(ALL INT(comm/10)) AS c3 C1 C2 C3 C4 C5 C6
,COUNT(DISTINCT INT(comm/10)) AS c4 -- -- -- -- -- --
,COUNT(DISTINCT INT(comm)) AS c5 35 24 24 19 24 2
,COUNT(DISTINCT INT(comm))/10 AS c6
FROM staff;
Figure 235, COUNT function examples
SELECT 'NO GP-BY' AS c1 ANSWER
,COUNT(*) AS c2 ============
FROM staff C1 C2
WHERE id = -1 -------- --
UNION NO GP-BY 0
SELECT 'GROUP-BY' AS c1
,COUNT(*) AS c2
FROM staff
WHERE id = -1
GROUP BY dept;
Figure 236, COUNT function with and without GROUP BY
Figure 237, COUNT_BIG function syntax
SELECT COUNT_BIG(*) AS c1 ANSWER
,COUNT_BIG(dept) AS c2 ===================
,COUNT_BIG(DISTINCT dept) AS c3 C1 C2 C3 C4 C5
,COUNT_BIG(DISTINCT dept/10) AS c4 --- --- --- --- ---
,COUNT_BIG(DISTINCT dept)/10 AS c5 35. 35. 8. 7. 0.
FROM STAFF;
Figure 238, COUNT_BIG function examples
Figure 239, COVARIANCE function syntax
WITH temp1(c1, c2, c3, c4) AS ANSWER
(VALUES (0 , 0 , 0 , RAND(1)) ===============================
UNION ALL COV11 COV12 COV23 COV34
SELECT c1 + 1 ------- ------- ------- -------
,c2 - 1 83666. -83666. -1.4689 -0.0004
,RAND()
,RAND()
FROM temp1
WHERE c1 <= 1000
)
SELECT DEC(COVARIANCE(c1,c1),6,0) AS cov11
,DEC(COVARIANCE(c1,c2),6,0) AS cov12
,DEC(COVARIANCE(c2,c3),6,4) AS cov23
,DEC(COVARIANCE(c3,c4),6,4) AS cov34
FROM temp1;
Figure 240, COVARIANCE function examples
Figure 241, GROUPING function syntax
SELECT dept ANSWER
,AVG(salary) AS salary ================
,GROUPING(dept) AS df DEPT SALARY DF
FROM staff ---- -------- --
GROUP BY ROLLUP(dept) 10 83365.86 0
ORDER BY dept; 15 60482.33 0
20 63571.52 0
38 60457.11 0
42 49592.26 0
51 83218.16 0
66 73015.24 0
84 66536.75 0
- 67932.78 1
Figure 242, GROUPING function example
Figure 243, MAX function syntax
SELECT MAX(dept) ANSWER
,MAX(ALL dept) ===============
,MAX(DISTINCT dept) 1 2 3 4
,MAX(DISTINCT dept/10) --- --- --- ---
FROM staff; 84 84 84 8
Figure 244, MAX function examples
SELECT MAX(hiredate) ANSWER
,CHAR(MAX(hiredate),USA) ================================
,MAX(CHAR(hiredate,USA)) 1 2 3
FROM employee; ---------- ---------- ----------
2006-12-15 12/15/2006 12/15/2006
Figure 245, MAX function with dates
SELECT MAX(id) AS id ANSWER
,MAX(CHAR(id)) AS chr ===================
,MAX(DIGITS(id)) AS dig ID CHR DIG
FROM staff; ------ ------ -----
350 90 00350
Figure 246, MAX function with numbers, 1 of 2
SELECT MAX(id - 250) AS id ANSWER
,MAX(CHAR(id - 250)) AS chr =====================
,MAX(DIGITS(id - 250)) AS dig ID CHR DIG
FROM staff; ----- ---- ----------
100 90 0000000240
Figure 247, MAX function with numbers, 2 of 2
Figure 248, MIN function syntax
SELECT MIN(dept) ANSWER
,MIN(ALL dept) ===============
,MIN(DISTINCT dept) 1 2 3 4
,MIN(DISTINCT dept/10) --- --- --- ---
FROM staff; 10 10 10 1
Figure 249, MIN function examples
Figure 250, REGRESSION functions syntax
ANSWERS
==========
SELECT DEC(REGR_SLOPE(bonus,salary) ,7,5) AS r_slope 0.00247
,DEC(REGR_INTERCEPT(bonus,salary),7,3) AS r_icpt 644.862
,INT(REGR_COUNT(bonus,salary) ) AS r_count 5
,INT(REGR_AVGX(bonus,salary) ) AS r_avgx 70850
,INT(REGR_AVGY(bonus,salary) ) AS r_avgy 820
,DEC(REGR_SXX(bonus,salary) ,10) AS r_sxx 8784575000
,INT(REGR_SXY(bonus,salary) ) AS r_sxy 21715000
,INT(REGR_SYY(bonus,salary) ) AS r_syy 168000
FROM employee
WHERE workdept = 'A00';
Figure 251, REGRESSION functions examples
Figure 252, STDDEV function syntax
ANSWER
===============================
A1 S1 S2 S3 S4
-- ------------- ---- ---- ----
SELECT AVG(dept) AS a1 41 +2.3522355E+1 23.5 23.5 24.1
,STDDEV(dept) AS s1
,DEC(STDDEV(dept),3,1) AS s2
,DEC(STDDEV(ALL dept),3,1) AS s3
,DEC(STDDEV(DISTINCT dept),3,1) AS s4
FROM staff;
Figure 253, STDDEV function examples
Figure 254, SUM function syntax
SELECT SUM(dept) AS s1 ANSWER
,SUM(ALL dept) AS s2 ========================
,SUM(DISTINCT dept) AS s3 S1 S2 S3 S4 S5
,SUM(dept/10) AS s4 ---- ---- ---- ---- ----
,SUM(dept)/10 AS s5 1459 1459 326 134 145
FROM staff;
Figure 255, SUM function examples
Figure 256, VARIANCE function syntax
ANSWER
==============================
A1 V1 V2 V3 V4
-- --------------- --- --- ---
SELECT AVG(dept) AS a1 41 +5.533012244E+2 553 553 582
,VARIANCE(dept) AS s1
,DEC(VARIANCE(dept),4,1) AS s2
,DEC(VARIANCE(ALL dept),4,1) AS s3
,DEC(VARIANCE(DISTINCT dept),4,1) AS s4
FROM staff;
Figure 257, VARIANCE function examples
SELECT s1.job, s1.id, s1.salary ANSWER
FROM staff s1 =================
WHERE s1.name LIKE '%s%' JOB ID SALARY
AND s1.id < 90 ----- -- --------
ORDER BY s1.job Clerk 80 43504.60
,s1.id; Mgr 10 98357.50
Mgr 50 80659.80
Figure 258, Select rows from STAFF table
SELECT s1.job, s1.id, s1.salary
,SUM(salary) OVER(ORDER BY job, id) AS sumsal
,ROW_NUMBER() OVER(ORDER BY job, id) AS r ANSWER
FROM staff s1 ======
WHERE s1.name LIKE '%s%' JOB ID SALARY SUMSAL R
AND s1.id < 90 ----- -- -------- --------- -
ORDER BY s1.job Clerk 80 43504.60 43504.60 1
,s1.id; Mgr 10 98357.50 141862.10 2
Mgr 50 80659.80 222521.90 3
Figure 259, Using OLAP functions to get additional fields
WITH temp1 AS ANSWER
(SELECT * =============================
FROM staff s1 JOB ID SALARY SUMSAL R
WHERE s1.name LIKE '%s%' ----- -- -------- --------- -
AND s1.id < 90 Clerk 80 43504.60 43504.60 1
) Mgr 10 98357.50 141862.10 2
SELECT s1.job, s1.id, s1.salary Mgr 50 80659.80 222521.90 3
,(SELECT SUM(s2.salary)
FROM temp1 s2
WHERE (s2.job < s1.job)
OR (s2.job = s1.job AND s2.id <= s1.id)) AS sumsal
,(SELECT COUNT(*)
FROM temp1 s2
WHERE (s2.job < s1.job)
OR (s2.job = s1.job AND s2.id <= s1.id)) AS r
FROM temp1 s1
ORDER BY s1.job
,s1.id;
Figure 260, Running counts without OLAP functions
Figure 261, Sample OLAP query
SELECT dept ,id
,salary
,DEC(AVG(salary) OVER() ,8,2) AS avg1
,DEC(AVG(salary) OVER(PARTITION BY dept) ,8,2) AS avg2
,DEC(AVG(salary) OVER(PARTITION BY dept
ORDER BY id
ROWS UNBOUNDED PRECEDING) ,8,2) AS avg3
,DEC(AVG(salary) OVER(PARTITION BY dept
ORDER BY id
ROWS BETWEEN 1 PRECEDING
AND 2 FOLLOWING) ,8,2) AS avg4
FROM staff
WHERE dept IN (15,20)
AND id > 20
ORDER BY dept ,id;
ANSWER
=====================================================
DEPT ID SALARY AVG1 AVG2 AVG3 AVG4
---- --- -------- -------- -------- -------- --------
15 50 80659.80 53281.11 60482.33 80659.80 66556.94
15 70 76502.83 53281.11 60482.33 78581.31 60482.33
15 110 42508.20 53281.11 60482.33 66556.94 53756.51
15 170 42258.50 53281.11 60482.33 60482.33 42383.35
20 80 43504.60 53281.11 38878.67 43504.60 38878.67
20 190 34252.75 53281.11 38878.67 38878.67 38878.67
Figure 262, Sample OLAP query
Figure 263, PARTITION BY syntax
SELECT id ,dept ,job ,years ,salary
,DEC(AVG(salary) OVER(PARTITION BY dept) ,7,2) AS dpt_avg
,DEC(AVG(salary) OVER(PARTITION BY job) ,7,2) AS job_avg
,DEC(AVG(salary) OVER(PARTITION BY years/2) ,7,2) AS yr2_avg
,DEC(AVG(salary) OVER(PARTITION BY dept, job) ,7,2) AS d_j_avg
FROM staff
WHERE dept IN (15,20)
AND id > 20
ORDER BY id;
ANSWER
=================================================================
ID DEPT JOB YEARS SALARY DPT_AVG JOB_AVG YR2_AVG D_J_AVG
--- ---- ----- ----- -------- -------- -------- -------- --------
50 15 Mgr 10 80659.80 60482.33 80659.80 80659.80 80659.80
70 15 Sales 7 76502.83 60482.33 76502.83 76502.83 76502.83
80 20 Clerk - 43504.60 38878.67 40631.01 43504.60 38878.67
110 15 Clerk 5 42508.20 60482.33 40631.01 42383.35 42383.35
170 15 Clerk 4 42258.50 60482.33 40631.01 42383.35 42383.35
190 20 Clerk 8 34252.75 38878.67 40631.01 34252.75 38878.67
Figure 264, PARTITION BY examples
SELECT dept ANSWER
,SUM(years) AS sum ================
,AVG(years) AS avg DEPT SUM AVG ROW
,COUNT(*) AS row ---- --- --- ---
FROM staff 15 22 7 3
WHERE id BETWEEN 40 AND 120 38 6 6 1
AND years IS NOT NULL 42 13 6 2
GROUP BY dept;
Figure 265, Sample query using GROUP BY
SELECT dept ANSWER
,SUM(years) OVER(PARTITION BY dept) AS sum =================
,AVG(years) OVER(PARTITION BY dept) AS avg DEPT SUM AVG ROW
,COUNT(*) OVER(PARTITION BY dept) AS row ----- --- --- ---
FROM staff 15 22 7 3
WHERE id BETWEEN 40 AND 120 15 22 7 3
AND years IS NOT NULL 15 22 7 3
ORDER BY dept; 38 6 6 1
42 13 6 2
42 13 6 2
Figure 266, Sample query using PARTITION
SELECT DISTINCT ANSWER
dept =================
,SUM(years) OVER(PARTITION BY dept) AS sum DEPT SUM AVG ROW
,AVG(years) OVER(PARTITION BY dept) AS avg ----- --- --- ---
,COUNT(*) OVER(PARTITION BY dept) AS row 15 22 7 3
FROM staff 38 6 6 1
WHERE id BETWEEN 40 AND 120 42 13 6 2
AND years IS NOT NULL
ORDER BY dept;
Figure 267, Sample query using PARTITION and DISTINCT
Figure 268, Moving window definition syntax
SELECT id ,salary
,DEC(AVG(salary) OVER() ,7,2) AS avg_all
,DEC(AVG(salary) OVER(ORDER BY id) ,7,2) AS avg_odr
,DEC(AVG(salary) OVER(ORDER BY id
ROWS BETWEEN UNBOUNDED PRECEDING
AND UNBOUNDED FOLLOWING) ,7,2) AS avg_p_f
,DEC(AVG(salary) OVER(ORDER BY id
ROWS BETWEEN UNBOUNDED PRECEDING
AND CURRENT ROW) ,7,2) AS avg_p_c
,DEC(AVG(salary) OVER(ORDER BY id
ROWS BETWEEN CURRENT ROW
AND UNBOUNDED FOLLOWING) ,7,2) AS avg_c_f
,DEC(AVG(salary) OVER(ORDER BY id
ROWS BETWEEN 2 PRECEDING
AND 1 FOLLOWING) ,7,2) AS avg_2_1
FROM staff
WHERE dept IN (15,20)
AND id > 20
ORDER BY id;
ANSWER
==================================================================
ID SALARY AVG_ALL AVG_ODR AVG_P_F AVG_P_C AVG_C_F AVG_2_1
--- -------- -------- -------- -------- -------- -------- --------
50 80659.80 53281.11 80659.80 53281.11 80659.80 53281.11 78581.31
70 76502.83 53281.11 78581.31 53281.11 78581.31 47805.37 66889.07
80 43504.60 53281.11 66889.07 53281.11 66889.07 40631.01 60793.85
110 42508.20 53281.11 60793.85 53281.11 60793.85 39673.15 51193.53
170 42258.50 53281.11 57086.78 53281.11 57086.78 38255.62 40631.01
190 34252.75 53281.11 53281.11 53281.11 53281.11 34252.75 39673.15
Figure 269, Different window sizes
SELECT id
,SUM(id) OVER(ORDER BY id) AS sum1
,SUM(id) OVER(ORDER BY id ROWS 1 PRECEDING) AS sum2
,SUM(id) OVER(ORDER BY id ROWS UNBOUNDED PRECEDING) AS sum3
,SUM(id) OVER(ORDER BY id ROWS CURRENT ROW) AS sum4
,SUM(id) OVER(ORDER BY id ROWS 2 FOLLOWING) AS sum5
,SUM(id) OVER(ORDER BY id ROWS UNBOUNDED FOLLOWING) AS sum6
FROM staff
WHERE id < 40 ANSWER
ORDER BY id; ================================
ID SUM1 SUM2 SUM3 SUM4 SUM5 SUM6
-- ---- ---- ---- ---- ---- ----
10 10 10 10 10 60 60
20 30 30 30 20 50 50
30 60 50 60 30 30 30
Figure 270, Different window sizes
SELECT id
,SMALLINT(SUM(id) OVER(ORDER BY id
RANGE BETWEEN 10 PRECEDING AND 10 FOLLOWING)) AS rng1
,SMALLINT(SUM(id) OVER(ORDER BY id
ROWS BETWEEN 1 PRECEDING AND 1 FOLLOWING)) AS row1
,SMALLINT(SUM(id) OVER(ORDER BY id
RANGE BETWEEN 10 PRECEDING AND CURRENT ROW)) AS rng2
,SMALLINT(SUM(id) OVER(ORDER BY id
ROWS BETWEEN 3 PRECEDING AND 1 PRECEDING)) AS row2
,SMALLINT(SUM(id) OVER(ORDER BY id DESC
ROWS BETWEEN 3 PRECEDING AND 1 PRECEDING)) AS row3
,SMALLINT(SUM(id) OVER(ORDER BY id
RANGE BETWEEN UNBOUNDED PRECEDING
AND 20 FOLLOWING)) AS rng3
FROM staff
WHERE id < 60
ORDER BY id; ANSWER
================================
ID RNG1 ROW1 RNG2 ROW2 ROW3 RNG3
-- ---- ---- ---- ---- ---- ----
10 30 30 10 - 90 60
20 60 60 30 10 120 100
30 90 90 50 30 90 150
40 120 120 70 60 50 150
50 90 90 90 90 - 150
Figure 271, ROW vs. RANGE example
Figure 272, ORDER BY syntax
SELECT dept ,name ,salary
,DEC(SUM(salary) OVER(ORDER BY dept) ,8,2) AS sum1
,DEC(SUM(salary) OVER(ORDER BY dept DESC) ,8,2) AS sum2
,DEC(SUM(salary) OVER(ORDER BY ORDER OF s1) ,8,2) AS sum3
,SMALLINT(RANK() OVER(ORDER BY salary, name, dept) ) AS r1
,SMALLINT(RANK() OVER(ORDER BY ORDER OF s1) ) AS r2
,ROW_NUMBER() OVER(ORDER BY salary) AS w1
,COUNT(*) OVER(ORDER BY salary) AS w2
FROM (SELECT *
FROM staff
WHERE id < 60
ORDER BY dept
,name
)AS s1
ORDER BY 1, 2;
ANSWER
================================================================
DEPT NAME SALARY SUM1 SUM2 SUM3 R1 R2 W1 W2
---- -------- -------- --------- --------- --------- -- -- -- --
15 Hanes 80659.80 80659.80 412701.30 80659.80 4 1 4 4
20 Pernal 78171.25 257188.55 332041.50 158831.05 3 2 3 3
20 Sanders 98357.50 257188.55 332041.50 257188.55 5 3 5 5
38 Marenghi 77506.75 412701.30 155512.75 334695.30 1 4 1 1
38 O'Brien 78006.00 412701.30 155512.75 412701.30 2 5 2 2
Figure 273, ORDER BY example
SELECT id SELECT id
,name ,name
,ROW_NUMBER() OVER( ,ROW_NUMBER() OVER(
ORDER BY ORDER OF s) od ORDER BY ORDER OF s) od
FROM (SELECT * FROM (SELECT *
FROM staff FROM staff
WHERE id < 50 WHERE id < 50
ORDER BY name ASC ORDER BY name DESC
)AS s )AS s
ORDER BY id ASC; ORDER BY id ASC;
ANSWER ANSWER
=============== ===============
ID NAME OD ID NAME OD
-- --------- -- -- --------- --
10 Sanders 4 10 Sanders 1
20 Pernal 3 20 Pernal 2
30 Marenghi 1 30 Marenghi 4
40 O'Brien 2 40 O'Brien 3
Figure 274, ORDER BY table designator examples
SELECT id
,years AS yr
,salary
,DENSE_RANK() OVER(ORDER BY years ASC) AS a
,DENSE_RANK() OVER(ORDER BY years ASC NULLS FIRST) AS af
,DENSE_RANK() OVER(ORDER BY years ASC NULLS LAST ) AS al
,DENSE_RANK() OVER(ORDER BY years DESC) AS d
,DENSE_RANK() OVER(ORDER BY years DESC NULLS FIRST) AS df
,DENSE_RANK() OVER(ORDER BY years DESC NULLS LAST ) AS dl
FROM staff
WHERE id < 100
ORDER BY years
,salary; ANSWER
==================================
ID YR SALARY A AF AL D DF DL
-- -- -------- -- -- -- -- -- --
30 5 77506.75 1 2 1 6 6 5
90 6 38001.75 2 3 2 5 5 4
40 6 78006.00 2 3 2 5 5 4
70 7 76502.83 3 4 3 4 4 3
10 7 98357.50 3 4 3 4 4 3
20 8 78171.25 4 5 4 3 3 2
50 10 80659.80 5 6 5 2 2 1
80 - 43504.60 6 1 6 1 1 6
60 - 66808.30 6 1 6 1 1 6
Figure 275, Overriding the default null ordering sequence
SELECT COUNT(DISTINCT years) AS y#1
,MAX(y#) AS y#2
FROM (SELECT years
,DENSE_RANK() OVER(ORDER BY years) AS y#
FROM staff
WHERE id < 100
)AS xxx ANSWER
ORDER BY 1; =======
Y#1 Y#2
--- ---
5 6
Figure 276, Counting distinct values - comparison
Figure 277, Ranking functions syntax
SELECT id
,years
,salary
,RANK() OVER(ORDER BY years) AS rank#
,DENSE_RANK() OVER(ORDER BY years) AS dense#
,ROW_NUMBER() OVER(ORDER BY years) AS row#
FROM staff
WHERE id < 100 ANSWER
AND years < 10 ===================================
ORDER BY years; ID YEARS SALARY RANK# DENSE# ROW#
-- ----- -------- ----- ------ ----
30 5 77506.75 1 1 1
40 6 78006.00 2 2 2
90 6 38001.75 2 2 3
10 7 98357.50 4 3 4
70 7 76502.83 4 3 5
20 8 78171.25 6 4 6
Figure 278, Ranking functions example
SELECT job AS job
,years AS yr
,id AS id
,name AS name
,RANK() OVER(ORDER BY job ASC ) AS a1
,RANK() OVER(ORDER BY job ASC, years ASC ) AS a2
,RANK() OVER(ORDER BY job ASC, years ASC ,id ASC ) AS a3
,RANK() OVER(ORDER BY job DESC ) AS d1
,RANK() OVER(ORDER BY job DESC, years DESC ) AS d2
,RANK() OVER(ORDER BY job DESC, years DESC, id DESC) AS d3
,RANK() OVER(ORDER BY job ASC, years DESC, id ASC ) AS m1
,RANK() OVER(ORDER BY job DESC, years ASC, id DESC) AS m2
FROM staff
WHERE id < 150
AND years IN (6,7) ANSWER
AND job > 'L' ===========================================
ORDER BY job JOB YR ID NAME A1 A2 A3 D1 2 D3 M1 M2
,years ----- -- --- ------- -- -- -- -- - -- -- --
,id; Mgr 6 140 Fraye 1 1 1 4 6 6 3 4
Mgr 7 10 Sanders 1 2 2 4 4 5 1 6
Mgr 7 100 Plotz 1 2 3 4 4 4 2 5
Sales 6 40 O'Brien 4 4 4 1 2 3 5 2
Sales 6 90 Koonitz 4 4 5 1 2 2 6 1
Sales 7 70 Rothman 4 6 6 1 1 1 4 3
Figure 279, ORDER BY usage
SELECT id ANSWER
,years AS yr =================
,salary ID YR SALARY R1
,RANK() OVER(PARTITION BY years -- -- -------- --
ORDER BY salary) AS r1 30 5 77506.75 1
FROM staff 40 6 78006.00 1
WHERE id < 80 70 7 76502.83 1
AND years IS NOT NULL 10 7 98357.50 2
ORDER BY years 20 8 78171.25 1
,salary; 50 0 80659.80 1
Figure 280, Values ranked by subset of rows
SELECT id
,years
,salary
,SMALLINT(RANK() OVER(ORDER BY years ASC)) AS rank_a
,SMALLINT(RANK() OVER(ORDER BY years DESC)) AS rank_d
,SMALLINT(RANK() OVER(ORDER BY id, years)) AS rank_iy
FROM STAFF
WHERE id < 100
AND years IS NOT NULL
ORDER BY years;
Figure 281, Multiple rankings in same query
SELECT id
,years
,name
,salary
,SMALLINT(RANK() OVER(ORDER BY SUBSTR(name,3,2))) AS dumb1
,SMALLINT(RANK() OVER(ORDER BY salary / 1000)) AS dumb2
,SMALLINT(RANK() OVER(ORDER BY years * ID)) AS dumb3
,SMALLINT(RANK() OVER(ORDER BY 1)) AS dumb4
FROM staff
WHERE id < 40
AND years IS NOT NULL
ORDER BY 1;
Figure 282, Dumb rankings, SQL
ID YEARS NAME SALARY DUMB1 DUMB2 DUMB3 DUMB4
-- ----- -------- -------- ----- ----- ----- -----
10 7 Sanders 98357.50 1 3 1 1
20 8 Pernal 78171.25 3 2 3 1
30 5 Marenghi 77506.75 2 1 2 1
Figure 283, Dumb ranking, Answer
SELECT xxx.* ANSWER
,RANK()OVER(ORDER BY id) AS r2 ================
FROM (SELECT id ID NAME R1 R2
,name -- ------- -- --
,RANK() OVER(ORDER BY id) AS r1 40 O'Brien 4 1
FROM staff 50 Hanes 5 2
WHERE id < 100 70 Rothman 6 3
AND years IS NOT NULL 90 Koonitz 7 4
)AS xxx
WHERE id > 30
ORDER BY id;
Figure 284, Subsequent processing of ranked data
SELECT id ANSWER
,RANK() OVER(PARTITION BY dept =================
ORDER BY salary DESC) AS r1 ID R1 SALARY DP
,salary -- -- -------- --
,dept AS dp 10 1 98357.50 20
FROM staff 50 1 80659.80 15
WHERE id < 80 40 1 78006.00 38
AND years IS NOT NULL 20 2 78171.25 20
ORDER BY r1 ASC 30 2 77506.75 38
,salary DESC; 70 2 76502.83 15
Figure 285, Ordering rows by rank, using RANK function
SELECT id ANSWER
,(SELECT COUNT(*) =================
FROM staff s2 ID R1 SALARY DP
WHERE s2.id < 80 -- -- -------- --
AND S2.YEARS IS NOT NULL 10 1 98357.50 20
AND s2.dept = s1.dept 50 1 80659.80 15
AND s2.salary >= s1.salary) AS R1 40 1 78006.00 38
,SALARY 20 2 78171.25 20
,dept AS dp 30 2 77506.75 38
FROM staff s1 70 2 76502.83 15
WHERE id < 80
AND years IS NOT NULL
ORDER BY r1 ASC
,salary DESC;
Figure 286, Ordering rows by rank, using sub-query
SELECT id ANSWER
,salary ==============
,dept AS dp ID SALARY DP
FROM (SELECT s1.* -- -------- --
,RANK() OVER(PARTITION BY dept 50 80659.80 15
ORDER BY salary DESC) AS r1 10 98357.50 20
FROM staff s1 40 78006.00 38
WHERE id < 80
AND years IS NOT NULL
)AS xxx
WHERE r1 = 1
ORDER BY dp;
Figure 287, Get highest salary in each department, use RANK function
SELECT id ANSWER
,salary ==============
,dept AS dp ID SALARY DP
FROM staff s1 -- -------- --
WHERE id < 80 50 80659.80 15
AND years IS NOT NULL 10 98357.50 20
AND NOT EXISTS 40 78006.00 38
(SELECT *
FROM staff s2
WHERE s2.id < 80
AND s2.years IS NOT NULL
AND s2.dept = s1.dept
AND s2.salary > s1.salary)
ORDER BY DP;
Figure 288, Get highest salary in each department, use correlated sub-query
SELECT id ANSWER
,salary ==============
,dept AS dp ID SALARY DP
FROM staff -- -------- --
WHERE id < 80 50 80659.80 15
AND years IS NOT NULL 10 98357.50 20
AND (dept, salary) IN 40 78006.00 38
(SELECT dept, MAX(salary)
FROM staff
WHERE id < 80
AND years IS NOT NULL
GROUP BY dept)
ORDER BY dp;
Figure 289, Get highest salary in each department, use uncorrelated sub-query
Figure 290, Numbering function syntax
SELECT id ANSWER
,name =================
,ROW_NUMBER() OVER() AS r1 ID NAME R1 R2
,ROW_NUMBER() OVER(ORDER BY id) AS r2 -- -------- -- --
FROM staff 10 Sanders 1 1
WHERE id < 50 20 Pernal 2 2
AND years IS NOT NULL 30 Marenghi 3 3
ORDER BY id; 40 O'Brien 4 4
Figure 291, ORDER BY example, 1 of 3
SELECT id ANSWER
,name =================
,ROW_NUMBER() OVER() AS r1 ID NAME R1 R2
,ROW_NUMBER() OVER(ORDER BY name) AS r2 -- -------- -- --
FROM staff 10 Sanders 4 4
WHERE id < 50 20 Pernal 3 3
AND years IS NOT NULL 30 Marenghi 1 1
ORDER BY id; 40 O'Brien 2 2
Figure 292, ORDER BY example, 2 of 3
SELECT id ANSWER
,name ====================
,ROW_NUMBER() OVER() AS r1 ID NAME R1 R2 R3
,ROW_NUMBER() OVER(ORDER BY ID) AS r2 -- -------- -- -- --
,ROW_NUMBER() OVER(ORDER BY NAME) AS r3 10 Sanders 1 1 4
FROM staff 20 Pernal 2 2 3
WHERE id < 50 30 Marenghi 3 3 1
AND years IS NOT NULL 40 O'Brien 4 4 2
ORDER BY id;
Figure 293, ORDER BY example, 3 of 3
SELECT job
,years
,id
,name
,ROW_NUMBER() OVER(PARTITION BY job ORDER BY years) AS row#
,RANK() OVER(PARTITION BY job ORDER BY years) AS rn1#
,DENSE_RANK() OVER(PARTITION BY job ORDER BY years) AS rn2#
FROM staff
WHERE id < 150 ANSWER
AND years IN (6,7) ======================================
AND job > 'L' JOB YEARS ID NAME ROW# RN1# RN2#
ORDER BY job ----- ----- --- ------- ---- ---- ----
,years; Mgr 6 140 Fraye 1 1 1
Mgr 7 10 Sanders 2 2 2
Mgr 7 100 Plotz 3 2 2
Sales 6 40 O'Brien 1 1 1
Sales 6 90 Koonitz 2 1 1
Sales 7 70 Rothman 3 3 2
Figure 294, Use of PARTITION phrase
SELECT * ANSWER
FROM (SELECT id =============
,name ID NAME R
,ROW_NUMBER() OVER(ORDER BY id) AS r -- -------- -
FROM staff 10 Sanders 1
WHERE id < 100 20 Pernal 2
AND years IS NOT NULL 30 Marenghi 3
)AS xxx
WHERE r <= 3
ORDER BY id;
Figure 295, Select first 3 rows, using ROW_NUMBER function
SELECT id ANSWER
,name =============
,ROW_NUMBER() OVER(ORDER BY id) AS r ID NAME R
FROM staff -- -------- -
WHERE id < 100 10 Sanders 1
AND years IS NOT NULL 20 Pernal 2
ORDER BY id 30 Marenghi 3
FETCH FIRST 3 ROWS ONLY;
Figure 296, Select first 3 rows, using FETCH FIRST notation
SELECT * ANSWER
FROM (SELECT id =============
,name ID NAME R
,ROW_NUMBER() OVER(ORDER BY id) AS r -- -------- -
FROM staff 30 Marenghi 3
WHERE id < 200 40 O'Brien 4
AND years IS NOT NULL 50 Hanes 5
)AS xxx 70 Rothman 6
WHERE r BETWEEN 3 AND 6
ORDER BY id;
Figure 297, Select 3rd through 6th rows
SELECT * ANSWER
FROM (SELECT id ==============
,name ID NAME R
,ROW_NUMBER() OVER(ORDER BY id) AS r --- ------- --
FROM staff 10 Sanders 1
WHERE id < 200 70 Rothman 6
AND years IS NOT NULL 140 Fraye 11
)AS xxx 190 Sneider 16
WHERE (r - 1) = ((r - 1) / 5) * 5
ORDER BY id;
Figure 298, Select every 5th matching row
SELECT *
FROM (SELECT id
,name
,ROW_NUMBER() OVER(ORDER BY id DESC) AS r
FROM staff ANSWER
WHERE id < 200 ==============
AND years IS NOT NULL ID NAME R
)AS xxx --- -------- -
WHERE r <= 2 180 Abrahams 2
ORDER BY id; 190 Sneider 1
Figure 299, Select last two rows
SELECT *
FROM (SELECT years
,id
,name
,RANK() OVER(ORDER BY years) AS rnk
,ROW_NUMBER() OVER(ORDER BY years, id) AS row
FROM staff
WHERE id < 200 ANSWER
AND years IS NOT NULL ==========================
)AS xxx YEARS ID NAME RNK ROW
WHERE rnk <= 3 ----- --- -------- --- ---
ORDER BY years 3 180 Abrahams 1 1
,id; 4 170 Kermisch 2 2
5 30 Marenghi 3 3
5 110 Ngan 3 4
Figure 300, Select first "n" rows, or more if needed
CREATE TABLE invoice
(inv# INTEGER NOT NULL
,customer# INTEGER NOT NULL
,sale_date DATE NOT NULL
,sale_value DECIMAL(9,2) NOT NULL
,CONSTRAINT ctx1 PRIMARY KEY (inv#)
,CONSTRAINT ctx2 CHECK(inv# >= 0));
Figure 301, Performance test table - definition
INSERT INTO invoice
WITH temp (n,m) AS
(VALUES (INTEGER(0),RAND(1))
UNION ALL
SELECT n+1, RAND()
FROM temp
WHERE n+1 < 1000000
)
SELECT n AS inv#
,INT(m * 1000) AS customer#
,DATE('2000-11-01') + (m*40) DAYS AS sale_date
,DECIMAL((m * m * 100),8,2) AS sale_value
FROM temp;
Figure 302, Performance test table - insert 1,000,000 rows
SELECT s.*
FROM invoice s
ORDER BY inv#
FETCH FIRST 5 ROWS ONLY;
Figure 303, Fetch first 5 rows - 0.000 elapsed seconds
SELECT s.*
FROM invoice s
ORDER BY inv#
FETCH FIRST 5 ROWS ONLY
OPTIMIZE FOR 5 ROWS;
Figure 304, Fetch first 5 rows - 0.000 elapsed seconds
SELECT s.*
,ROW_NUMBER() OVER() AS row#
FROM invoice s
ORDER BY inv#
FETCH FIRST 5 ROWS ONLY;
Figure 305, Fetch first 5 rows+ number rows - 0.000 elapsed seconds
SELECT *
FROM (SELECT s.*
,ROW_NUMBER() OVER() AS row#
FROM invoice s
)xxx
ORDER BY inv#
FETCH FIRST 5 ROWS ONLY;
Figure 306, Fetch first 5 rows+ number rows - 0.000 elapsed seconds
SELECT *
FROM (SELECT s.*
,ROW_NUMBER() OVER() AS row#
FROM invoice s
)xxx
WHERE row# <= 5
ORDER BY inv#;
Figure 307, Process and number all rows - 0.049 elapsed seconds
SELECT *
FROM (SELECT s.*
,ROW_NUMBER() OVER(ORDER BY inv#) AS row#
FROM invoice s
)xxx
WHERE row# <= 5
ORDER BY inv#;
Figure 308, Process and number 5 rows only - 0.000 elapsed seconds
WITH temp (inv#, c#, sd, sv, n) AS
(SELECT inv.*
,1
FROM invoice inv
WHERE inv# =
(SELECT MIN(inv#)
FROM invoice)
UNION ALL
SELECT new.*, n + 1
FROM temp old
,invoice new
WHERE old.inv# < new.inv#
AND old.n < 5
AND new.inv# =
(SELECT MIN(xxx.inv#)
FROM invoice xxx
WHERE xxx.inv# > old.inv#)
)
SELECT *
FROM temp;
Figure 309, Fetch first 5 rows - 0.000 elapsed seconds
Figure 310, Function syntax
SELECT dept ,id ,name ANSWER
,FIRST_VALUE(name) ==========================
OVER(PARTITION BY dept DEPT ID NAME FRST
ORDER BY id) AS frst ---- --- -------- --------
FROM staff 10 210 Lu Lu
WHERE dept <= 15 10 240 Daniels Lu
AND id > 160 10 260 Jones Lu
ORDER BY dept ,id; 15 170 Kermisch Kermisch
Figure 311, FIRST_NAME function example
SELECT dept ,id ,comm
,FIRST_VALUE(comm)
OVER(PARTITION BY dept ORDER BY comm) AS first1
,FIRST_VALUE(comm)
OVER(PARTITION BY dept ORDER BY comm NULLS FIRST) AS first2
,FIRST_VALUE(comm)
OVER(PARTITION BY dept ORDER BY comm NULLS LAST) AS first3
,FIRST_VALUE(comm)
OVER(PARTITION BY dept ORDER BY comm NULLS LAST
ROWS BETWEEN 1 PRECEDING AND CURRENT ROW) AS first4
,LAST_VALUE(comm)
OVER(PARTITION BY dept ORDER BY comm) AS last1
,LAST_VALUE(comm)
OVER(PARTITION BY dept ORDER BY comm NULLS FIRST
ROWS UNBOUNDED FOLLOWING) AS last2
FROM staff
WHERE id < 100
AND dept < 30
ORDER BY dept ,comm;
ANSWER
=================================================================
DEPT ID COMM FIRST1 FIRST2 FIRST3 FIRST4 LAST1 LAST2
---- -- ------- ------- ------- ------- ------- ------- ---------
15 70 1152.00 1152.00 - 1152.00 1152.00 1152.00 1152.00
15 50 - 1152.00 - 1152.00 1152.00 - 1152.00
20 80 128.20 128.20 - 128.20 128.20 128.20 612.45
20 20 612.45 128.20 - 128.20 128.20 612.45 612.45
20 10 - 128.20 - 128.20 612.45 - 612.45
Figure 312, Function examples
SELECT dept ,id ,comm
,FIRST_VALUE(comm)
OVER(PARTITION BY dept ORDER BY comm) AS rn_lst
,FIRST_VALUE(comm)
OVER(PARTITION BY dept ORDER BY comm NULLS LAST) AS rn_ls2
,FIRST_VALUE(comm)
OVER(PARTITION BY dept ORDER BY comm NULLS FIRST) AS rn_fst
,FIRST_VALUE(comm,'IGNORE NULLS')
OVER(PARTITION BY dept ORDER BY comm NULLS FIRST) AS in_fst
FROM staff
WHERE id BETWEEN 20 AND 160
AND dept <= 20 ANSWER
ORDER BY dept ,comm; ============================================
DEPT ID COMM RN_LST RN_LS2 RN_FST IN_FST
---- --- ------- ------ ------ ------ ------
10 160 - - - - -
15 110 206.60 206.60 206.60 - 206.60
15 70 1152.00 206.60 206.60 - 206.60
15 50 - 206.60 206.60 - -
20 80 128.20 128.20 128.20 128.20 128.20
20 20 612.45 128.20 128.20 128.20 128.20
Figure 313, Null value processing
Figure 314, Function syntax
SELECT dept ,id ,comm
,LAG(comm) OVER(PARTITION BY dept ORDER BY comm) AS lag1
,LAG(comm,0) OVER(PARTITION BY dept ORDER BY comm) AS lag2
,LAG(comm,2) OVER(PARTITION BY dept ORDER BY comm) AS lag3
,LAG(comm,1,-1,'IGNORE NULLS')
OVER(PARTITION BY dept ORDER BY comm) AS lag4
,LEAD(comm) OVER(PARTITION BY dept ORDER BY comm) AS led1
FROM staff
WHERE id BETWEEN 20 AND 160
AND dept <= 20
ORDER BY dept ,comm;
ANSWER
========================================================
DEPT ID COMM LAG1 LAG2 LAG3 LAG4 LED1
---- --- ------- ------- ------- ------- ------- -------
10 160 - - - - -1.00 -
15 110 206.60 - 206.60 - -1.00 1152.00
15 70 1152.00 206.60 1152.00 - 206.60 -
15 50 - 1152.00 - 206.60 1152.00 -
20 80 128.20 - 128.20 - -1.00 612.45
20 20 612.45 128.20 612.45 - 128.20 -
Figure 315, LAG and LEAD function Examples
Figure 316, Aggregation function syntax
SELECT id ,name ,salary
,SUM(salary) OVER() AS sum_sal
,AVG(salary) OVER() AS avg_sal
,MIN(salary) OVER() AS min_sal
,MAX(salary) OVER() AS max_sal
,COUNT(*) OVER() AS #rows
FROM staff
WHERE id < 30
ORDER BY id;
ANSWER
==============================================================
ID NAME SALARY SUM_SAL AVG_SAL MIN_SAL MAX_SAL #ROWS
-- -------- -------- --------- -------- -------- -------- ----
10 Sanders 98357.50 254035.50 84678.50 77506.75 98357.50 3
20 Pernal 78171.25 254035.50 84678.50 77506.75 98357.50 3
30 Marenghi 77506.75 254035.50 84678.50 77506.75 98357.50 3
Figure 317, Aggregation function, basic usage
SELECT id
,name
,salary
,SUM(salary) OVER() AS sum1
,SUM(salary) OVER(ORDER BY id * 0) AS sum2
,SUM(salary) OVER(ORDER BY 'ABC') AS sum3
,SUM(salary) OVER(ORDER BY 'ABC'
RANGE BETWEEN UNBOUNDED PRECEDING
AND UNBOUNDED FOLLOWING) AS sum4
FROM staff
WHERE id < 60
ORDER BY id;
ANSWER
============================================================
ID NAME SALARY SUM1 SUM2 SUM3 SUM4
-- -------- -------- --------- --------- --------- ---------
10 Sanders 98357.50 412701.30 412701.30 412701.30 412701.30
20 Pernal 78171.25 412701.30 412701.30 412701.30 412701.30
30 Marenghi 77506.75 412701.30 412701.30 412701.30 412701.30
40 O'Brien 78006.00 412701.30 412701.30 412701.30 412701.30
50 Hanes 80659.80 412701.30 412701.30 412701.30 412701.30
Figure 318, Logically equivalent aggregation functions
SELECT dept
,name
,salary
,SUM(salary) OVER(ORDER BY dept) AS sum1
,SUM(salary) OVER(ORDER BY dept DESC) AS sum2
,SUM(salary) OVER(ORDER BY dept, NAME) AS sum3
,SUM(salary) OVER(ORDER BY dept DESC, name DESC) AS sum4
,COUNT(*) OVER(ORDER BY dept) AS rw1
,COUNT(*) OVER(ORDER BY dept, NAME) AS rw2
FROM staff
WHERE id < 60
ORDER BY dept
,name;
ANSWER
======================================================================
DEPT NAME SALARY SUM1 SUM2 SUM3 SUM4 RW1 RW2
---- -------- -------- --------- --------- --------- --------- --- ---
15 Hanes 80659.80 80659.80 412701.30 80659.80 412701.30 1 1
20 Pernal 78171.25 257188.55 332041.50 158831.05 332041.50 3 2
20 Sanders 98357.50 257188.55 332041.50 257188.55 253870.25 3 3
38 Marenghi 77506.75 412701.30 155512.75 334695.30 155512.75 5 4
38 O'Brien 78006.00 412701.30 155512.75 412701.30 78006.00 5 5
Figure 319, Aggregation function, ORDER BY usage
SELECT id ,years
,AVG(years) OVER() AS "p_f"
,AVG(years) OVER(ORDER BY id
ROWS BETWEEN UNBOUNDED PRECEDING
AND UNBOUNDED FOLLOWING) AS "p_f"
,AVG(years) OVER(ORDER BY id) AS "p_c"
,AVG(years) OVER(ORDER BY id
ROWS BETWEEN UNBOUNDED PRECEDING
AND CURRENT ROW) AS "p_c"
,AVG(years) OVER(ORDER BY id
ROWS UNBOUNDED PRECEDING) AS "p_c"
,AVG(years) OVER(ORDER BY id
ROWS UNBOUNDED FOLLOWING) AS "c_f"
,AVG(years) OVER(ORDER BY id
ROWS 2 FOLLOWING) AS "c_2"
,AVG(years) OVER(ORDER BY id
ROWS 1 PRECEDING) AS "1_c"
,AVG(years) OVER(ORDER BY id
ROWS BETWEEN 1 FOLLOWING
AND 2 FOLLOWING) AS "1_2"
FROM staff
WHERE dept IN (15,20)
AND id > 20 ANSWER
AND years > 1 =============================================
ORDER BY id; ID YEARS p_f p_f p_c p_c p_c c_f c_2 1_c 1_2
--- ----- --- --- --- --- --- --- --- --- ---
50 10 6 6 10 10 10 6 7 10 6
70 7 6 6 8 8 8 6 5 8 4
110 5 6 6 7 7 7 5 5 6 6
170 4 6 6 6 6 6 6 6 4 8
190 8 6 6 6 6 6 8 8 6 -
Figure 320, ROWS usage examples
SELECT dept
,name
,years
,SMALLINT(SUM(years) OVER(ORDER BY dept
ROWS BETWEEN 1 PRECEDING
AND CURRENT ROW)) AS row1
,SMALLINT(SUM(years) OVER(ORDER BY dept
ROWS BETWEEN 2 PRECEDING
AND CURRENT ROW)) AS row2
,SMALLINT(SUM(years) OVER(ORDER BY dept
RANGE BETWEEN 1 PRECEDING
AND CURRENT ROW)) AS rg01
,SMALLINT(SUM(years) OVER(ORDER BY dept
RANGE BETWEEN 10 PRECEDING
AND CURRENT ROW)) AS rg10
,SMALLINT(SUM(years) OVER(ORDER BY dept
RANGE BETWEEN 20 PRECEDING
AND CURRENT ROW)) AS rg20
,SMALLINT(SUM(years) OVER(ORDER BY dept
RANGE BETWEEN 10 PRECEDING
AND 20 FOLLOWING)) AS rg11
,SMALLINT(SUM(years) OVER(ORDER BY dept
RANGE BETWEEN CURRENT ROW
AND 20 FOLLOWING)) AS rg99
FROM staff
WHERE id < 100
AND years IS NOT NULL
ORDER BY dept
,name;
ANSWER
=======================================================
DEPT NAME YEARS ROW1 ROW2 RG01 RG10 RG20 RG11 RG99
------ ------- ----- ---- ---- ---- ---- ---- ---- ----
15 Hanes 10 10 10 17 17 17 32 32
15 Rothman 7 17 17 17 17 17 32 32
20 Pernal 8 15 25 15 32 32 43 26
20 Sanders 7 15 22 15 32 32 43 26
38 Marengh 5 12 20 11 11 26 17 17
38 O'Brien 6 11 18 11 11 26 17 17
42 Koonitz 6 12 17 6 17 17 17 6
Figure 321, RANGE usage
SELECT id
,name
,SMALLINT(SUM(id) OVER(ORDER BY id ASC
ROWS BETWEEN 1 PRECEDING
AND CURRENT ROW)) AS apc
,SMALLINT(SUM(id) OVER(ORDER BY id ASC
ROWS BETWEEN CURRENT ROW
AND 1 FOLLOWING)) AS acf
,SMALLINT(SUM(id) OVER(ORDER BY id DESC
ROWS BETWEEN 1 PRECEDING
AND CURRENT ROW)) AS dpc
,SMALLINT(SUM(id) OVER(ORDER BY id DESC
ROWS BETWEEN CURRENT ROW
AND 1 FOLLOWING)) AS dcf
FROM staff
WHERE id < 50
AND years IS NOT NULL ANSWER
ORDER BY id; ===========================
ID NAME APC ACF DPC DCF
-- -------- --- --- --- ---
10 Sanders 10 30 30 10
20 Pernal 30 50 50 30
30 Marenghi 50 70 70 50
40 O'Brien 70 40 40 70
Figure 322,BETWEEN and ORDER BY usage
ASC id (10,20,30,40)
READ ROWS, LEFT to RIGHT 1ST-ROW 2ND-ROW 3RD-ROW 4TH-ROW
========================== ======== ======== ======== ========
1 PRECEDING to CURRENT ROW 10=10 10+20=30 20+30=40 30+40=70
CURRENT ROW to 1 FOLLOWING 10+20=30 20+30=50 30+40=70 40 =40
DESC id (40,30,20,10)
READ ROWS, RIGHT to LEFT 1ST-ROW 2ND-ROW 3RD-ROW 4TH-ROW
========================== ======== ======== ======== ========
1 PRECEDING to CURRENT ROW 20+10=30 30+20=50 40+30=70 40 =40
CURRENT ROW to 1 FOLLOWING 10 =10 20+10=30 30+20=50 40+30=70
NOTE: Preceding row is always on LEFT of current row.
Following row is always on RIGHT of current row.
Figure 323, Explanation of query
CREATE VIEW scalar (d1,f1,s1,c1,v1,ts1,dt1,tm1,tc1) AS
WITH temp1 (n1, c1, t1) AS
(VALUES (-2.4,'ABCDEF','1996-04-22-23.58.58.123456')
,(+0.0,'ABCD ','1996-08-15-15.15.15.151515')
,(+1.8,'AB ','0001-01-01-00.00.00.000000'))
SELECT DECIMAL(n1,3,1)
,DOUBLE(n1)
,SMALLINT(n1)
,CHAR(c1,6)
,VARCHAR(RTRIM(c1),6)
,TIMESTAMP(t1)
,DATE(t1)
,TIME(t1)
,CHAR(t1)
FROM temp1;
Figure 324, Sample View DDL - Scalar functions
D1 F1 S1 C1 V1 TS1
------ --------- -- ------ ------ --------------------------
-2.4 -2.4e+000 -2 ABCDEF ABCDEF 1996-04-22-23.58.58.123456
0.0 0.0e+000 0 ABCD ABCD 1996-08-15-15.15.15.151515
1.8 1.8e+000 1 AB AB 0001-01-01-00.00.00.000000
DT1 TM1 TC1
---------- -------- --------------------------
1996-04-22 23:58:58 1996-04-22-23.58.58.123456
1996-08-15 15:15:15 1996-08-15-15.15.15.151515
0001-01-01 00:00:00 0001-01-01-00.00.00.000000
Figure 325, SCALAR view, contents (3 rows)
SELECT d1 AS d1 ANSWER (float output shortened)
,ABS(D1) AS d2 ================================
,f1 AS f1 D1 D2 F1 F2
,ABS(f1) AS f2 ---- --- ---------- ---------
FROM scalar; -2.4 2.4 -2.400e+0 2.400e+00
0.0 0.0 0.000e+0 0.000e+00
1.8 1.8 1.800e+0 1.800e+00
Figure 326, ABS function examples
SELECT c1 ANSWER
,ASCII(c1) AS ac1 ================
,ASCII(SUBSTR(c1,2)) AS ac2 C1 AC1 AC2
FROM scalar ------ --- ---
WHERE c1 = 'ABCDEF'; ABCDEF 65 66
Figure 327, ASCII function examples
WITH temp (big) AS ANSWER
(VALUES BIGINT(1) ====================
UNION ALL BIG
SELECT big * 256 --------------------
FROM temp 1
WHERE big < 1E16 256
) 65536
SELECT big 16777216
FROM temp; 4294967296
1099511627776
281474976710656
72057594037927936
Figure 328, BIGINT function example
WITH temp (f1) AS
(VALUES FLOAT(1.23456789)
UNION ALL
SELECT f1 * 100
FROM temp
WHERE f1 < 1E18
)
SELECT f1 AS float1
,DEC(f1,19) AS decimal1
,BIGINT(f1) AS bigint1
FROM temp;
Figure 329, Convert FLOAT to DECIMAL and BIGINT, SQL
FLOAT1 DECIMAL1 BIGINT1
---------------------- ------------------- --------------------
+1.23456789000000E+000 1. 1
+1.23456789000000E+002 123. 123
+1.23456789000000E+004 12345. 12345
+1.23456789000000E+006 1234567. 1234567
+1.23456789000000E+008 123456789. 123456788
+1.23456789000000E+010 12345678900. 12345678899
+1.23456789000000E+012 1234567890000. 1234567889999
+1.23456789000000E+014 123456789000000. 123456788999999
+1.23456789000000E+016 12345678900000000. 12345678899999996
+1.23456789000000E+018 1234567890000000000. 1234567889999999488
Figure 330, Convert FLOAT to DECIMAL and BIGINT, answer
Figure 331, BIT functions syntax
WITH ANSWER
temp1 (b1, b2) AS ===============================
(VALUES ( 1, 0) ,( 0, 1) B1 B2 hex1 hex2 and ano or xor
,( 0, 0) ,( 1, 1) -- -- ---- ---- --- --- --- ---
,( 2, 1) ,(15,-7) 1 0 0100 0000 0 1 1 1
,(15, 7) ,(-1, 1) 0 1 0000 0100 0 0 1 1
,(15,63) ,(63,31) 0 0 0000 0000 0 0 0 0
,(99,64) ,( 0,-2)), 1 1 0100 0100 1 0 1 0
temp2 (b1, b2) AS 2 1 0200 0100 0 2 3 3
(SELECT SMALLINT(b1) 15 -7 0F00 F9FF 9 6 -1 -10
,SMALLINT(b2) 15 7 0F00 0700 7 8 15 8
FROM temp1) -1 1 FFFF 0100 1 -2 -1 -2
SELECT b1 ,b2 15 63 0F00 3F00 15 0 63 48
,HEX(b1) AS "hex1" 63 31 3F00 1F00 31 32 63 32
,HEX(b2) AS "hex2" 99 64 6300 4000 64 35 99 35
,BITAND(b1,b2) AS "and" 0 -2 0000 FEFF 0 0 -2 -2
,BITANDNOT(b1,b2) AS "ano"
,BITOR(b1,b2) AS "or"
,BITXOR(b1,b2) AS "xor"
FROM temp2;
Figure 332, BIT functions examples
CREATE FUNCTION bitdisplay(inparm SMALLINT)
RETURNS CHAR(16)
BEGIN ATOMIC
DECLARE outstr VARCHAR(16);
DECLARE inval INT;
IF inparm >= 0 THEN
SET inval = inparm;
ELSE
SET inval = INT(65536) + inparm;
END IF;
SET outstr = '';
WHILE inval > 0 DO
SET outstr = STRIP(CHAR(MOD(inval,2))) || outstr;
SET inval = inval / 2;
END WHILE;
RETURN RIGHT(REPEAT('0',16) || outstr,16);
END!
Figure 333, Function to display SMALLINT bits
WITH ANSWER
temp1 (b1) AS ============================
(VALUES (32767) ,(16383) B1 hex1 bit_display
,( 4096) ,( 118) ------ ---- ----------------
,( 63) ,( 16) 32767 FF7F 0111111111111111
,( 2) ,( 1) 16383 FF3F 0011111111111111
,( 0) ,( -1) 4096 0010 0001000000000000
,( -2) ,( -3) 118 7600 0000000001110110
,( -64) ,(-32768) 63 3F00 0000000000111111
), 16 1000 0000000000010000
temp2 (b1) AS 2 0200 0000000000000010
(SELECT SMALLINT(b1) 1 0100 0000000000000001
FROM temp1 0 0000 0000000000000000
) -1 FFFF 1111111111111111
SELECT b1 -2 FEFF 1111111111111110
,HEX(b1) AS "hex1" -3 FDFF 1111111111111101
,BITDISPLAY(b1) AS "bit_display" -64 C0FF 1111111111000000
FROM temp2; -32768 0080 1000000000000000
Figure 334, BIT_DISPLAY function example
WITH
temp1 (b1) AS
(VALUES (32767),(21845),( 4096),( 0),( -1),( -64)
),
temp2 (b1, s15) AS
(SELECT SMALLINT(b1)
,SMALLINT(15)
FROM temp1
)
SELECT b1
,BITDISPLAY(b1) AS "b1_display"
,BITXOR(b1,s15) AS "xor"
,BITDISPLAY(BITXOR(b1,s15)) AS "xor_display"
,BITANDNOT(b1,s15) AS "andnot"
,BITDISPLAY(BITANDNOT(b1,s15)) AS "andnot_display"
FROM temp2;
Figure 335, Update bits #1, query
B1 b1_display xor xor_display andnot andnot_display
----- ---------------- ------ ---------------- ------ ----------------
32767 0111111111111111 32752 0111111111110000 32752 0111111111110000
21845 0101010101010101 21850 0101010101011010 21840 0101010101010000
4096 0001000000000000 4111 0001000000001111 4096 0001000000000000
0 0000000000000000 15 0000000000001111 0 0000000000000000
-1 1111111111111111 -16 1111111111110000 -16 1111111111110000
-64 1111111111000000 -49 1111111111001111 -64 1111111111000000
Figure 336, Update bits #1, answer
WITH
temp1 (b1) AS
(VALUES (32767),(21845),( 4096),( 0),( -1),( -64)
),
temp2 (b1, s15) AS
(SELECT SMALLINT(b1)
,SMALLINT(15)
FROM temp1
)
SELECT b1
,BITDISPLAY(b1) AS "b1_display"
,BITAND(b1,s15) AS "and"
,BITDISPLAY(BITAND(b1,s15)) AS "and_display"
,BITNOT(b1) AS "not"
,BITDISPLAY(BITNOT(b1)) AS "not_display"
FROM temp2;
Figure 337, Update bits #2, query
B1 b1_display and and_display not not_display
----- ---------------- ------ ---------------- ------ ----------------
32767 0111111111111111 15 0000000000001111 -32768 1000000000000000
21845 0101010101010101 5 0000000000000101 -21846 1010101010101010
4096 0001000000000000 0 0000000000000000 -4097 1110111111111111
0 0000000000000000 0 0000000000000000 -1 1111111111111111
-1 1111111111111111 15 0000000000001111 0 0000000000000000
-64 1111111111000000 0 0000000000000000 63 0000000000111111
Figure 338, Update bits #2, answer
Figure 339, BLOB function syntax
Figure 340, CEILING function syntax
SELECT d1 ANSWER (float output shortened)
,CEIL(d1) AS d2 ==================================
,f1 D1 D2 F1 F2
,CEIL(f1) AS f2 ---- ---- ---------- ----------
FROM scalar; -2.4 -2. -2.400E+0 -2.000E+0
0.0 0. +0.000E+0 +0.000E+0
1.8 2. +1.800E+0 +2.000E+0
Figure 341, CEIL function examples
Figure 342, CHAR function syntax
SELECT name ANSWER
,CHAR(name,3) =====================================
,comm NAME 2 COMM 4 5
,CHAR(comm) ------- --- ------- -------- --------
,CHAR(comm,'@') James Jam 128.20 00128.20 00128@20
FROM staff Koonitz Koo 1386.70 01386.70 01386@70
WHERE id BETWEEN 80 Plotz Plo - - -
AND 100
ORDER BY id;
Figure 343, CHAR function examples - characters and numbers
ANSWER
==========================================
INT CHAR_INT CHAR_FLT CHAR_DEC
-------- -------- ----------- ------------
WITH temp1 (n) AS 3 3 3.0E0 00000000003.
(VALUES (3) 9 9 9.0E0 00000000009.
UNION ALL 81 81 8.1E1 00000000081.
SELECT n * n 6561 6561 6.561E3 00000006561.
FROM temp1 43046721 43046721 4.3046721E7 00043046721.
WHERE n < 9000
)
SELECT n AS int
,CHAR(INT(n)) AS char_int
,CHAR(FLOAT(n)) AS char_flt
,CHAR(DEC(n)) AS char_dec
FROM temp1;
Figure 344, CHAR function examples - positive numbers
WITH temp1 (n1, n2) AS ANSWER
(VALUES (SMALLINT(+3) ===================================
,SMALLINT(-7)) N1 I1 I2 D1 D2
UNION ALL ------ ----- ------ ------- -------
SELECT n1 * n2 3 3 +3 00003. +00003.
,n2 -21 -21 -21 -00021. -00021.
FROM temp1 147 147 +147 00147. +00147.
WHERE n1 < 300 -1029 -1029 -1029 -01029. -01029.
) 7203 7203 +7203 07203. +07203.
SELECT n1
,CHAR(n1) AS i1
,CASE
WHEN n1 < 0 THEN CHAR(n1)
ELSE '+' CONCAT CHAR(n1)
END AS i2
,CHAR(DEC(n1)) AS d1
,CASE
WHEN n1 < 0 THEN CHAR(DEC(n1))
ELSE '+' CONCAT CHAR(DEC(n1))
END AS d2
FROM temp1;
Figure 345, Align CHAR function output - numbers
ANSWER
==========
SELECT CHAR(CURRENT DATE,ISO) AS iso ==> 2005-11-30
,CHAR(CURRENT DATE,EUR) AS eur ==> 30.11.2005
,CHAR(CURRENT DATE,JIS) AS jis ==> 2005-11-30
,CHAR(CURRENT DATE,USA) AS usa ==> 11/30/2005
FROM sysibm.sysdummy1;
Figure 346, CHAR function examples - date value
ANSWER
========
SELECT CHAR(CURRENT TIME,ISO) AS iso ==> 19.42.21
,CHAR(CURRENT TIME,EUR) AS eur ==> 19.42.21
,CHAR(CURRENT TIME,JIS) AS jis ==> 19:42:21
,CHAR(CURRENT TIME,USA) AS usa ==> 07:42 PM
FROM sysibm.sysdummy1;
Figure 347, CHAR function examples - time value
SELECT CHAR(CURRENT TIMESTAMP) ANSWER
FROM sysibm.sysdummy1; ==========================
2005-11-30-19.42.21.873002
Figure 348, CHAR function example - timestamp value
SELECT d2 ANSWER
,CHAR(d2) AS cd2 ================
,DIGITS(d2) AS dd2 D2 CD2 DD2
FROM (SELECT DEC(d1,4,1) AS d2 ---- ------ ----
FROM scalar -2.4 -002.4 0024
)AS xxx 0.0 000.0 0000
ORDER BY 1; 1.8 001.8 0018
Figure 349, DIGITS vs. CHAR
Figure 350, CHARACTER_LENGTH function syntax
WITH temp1 (c1) AS (VALUES (CAST('ÁÉÌ' AS VARCHAR(10))))
SELECT c1 AS C1
,LENGTH(c1) AS LEN
,OCTET_LENGTH(c1) AS OCT ANSWER
,CHAR_LENGTH(c1,OCTETS) AS L08 =======================
,CHAR_LENGTH(c1,CODEUNITS16) AS L16 C1 LEN OCT L08 L16 L32
,CHAR_LENGTH(c1,CODEUNITS32) AS L32 --- --- --- --- --- ---
FROM temp1; ÁÉÌ 6 6 6 3 3
Figure 351,CHARACTER_LENGTH function example
SELECT 'A' AS "c" ANSWER
,ASCII('A') AS "c>n" =================
,CHR(ASCII('A')) AS "c>n>c" C C>N C>N>C NL
,CHR(333) AS "nl" - --- ----- --
FROM staff A 65 A ÿ
WHERE id = 10;
Figure 352, CHR function examples
SELECT c1 ANSWER
,CLOB(c1) AS cc1 ===================
,CLOB(c1,3) AS cc2 C1 CC1 CC2
FROM scalar; ------ ------ ---
ABCDEF ABCDEF ABC
ABCD ABCD ABC
AB AB AB
Figure 353, CLOB function examples
SELECT id ANSWER
,comm ==================
,COALESCE(comm,0) ID COMM 3
FROM staff -- ------ ------
WHERE id < 30 10 - 0.00
ORDER BY id; 20 612.45 612.45
Figure 354, COALESCE function example
WITH temp1(c1,c2,c3) AS ANSWER
(VALUES (CAST(NULL AS SMALLINT) ========
,CAST(NULL AS SMALLINT) CC1 CC2
,CAST(10 AS SMALLINT))) --- ---
SELECT COALESCE(c1,c2,c3) AS cc1 10 10
,CASE
WHEN c1 IS NOT NULL THEN c1
WHEN c2 IS NOT NULL THEN c2
WHEN c3 IS NOT NULL THEN c3
END AS cc2
FROM TEMP1;
Figure 355, COALESCE and equivalent CASE expression
SELECT COUNT(*) AS #rows ANSWER
,MIN(id) AS min_id ===================
,COALESCE(MIN(id),-1) AS ccc_id #ROWS MIN_ID CCC_ID
FROM staff ----- ------ ------
WHERE id < 5; 0 - -1
Figure 356, NOT NULL field returning null value
WITH temp1 (c1) As
(VALUES ('a'),('A'),('Á'),('Ä'),('b'))
SELECT c1
,COLLATION_KEY_BIT(c1,'UCA400R1_S1',9) AS "a=A=Á=Ä"
,COLLATION_KEY_BIT(c1,'UCA400R1_S2',9) AS "a=A<Á<Ä"
,COLLATION_KEY_BIT(c1,'UCA400R1_S3',9) AS "a 10; ---------- ----
1996-04-22 22
1996-08-15 15
Figure 367, DAY function examples
SELECT dt1 ANSWER
,DAY(dt1) AS day1 =========================
,dt1 -'1996-04-30' AS dur2 DT1 DAY1 DUR2 DAY2
,DAY(dt1 -'1996-04-30') AS day2 ---------- ---- ---- ----
FROM scalar 1996-04-22 22 -8. -8
WHERE DAY(dt1) > 10 1996-08-15 15 315. 15
ORDER BY dt1;
Figure 368, DAY function, using date-duration input
SELECT dt1 ANSWER
,DAYNAME(dt1) AS dy1 ========================
,LENGTH(DAYNAME(dt1)) AS dy2 DT1 DY1 DY2
FROM scalar ---------- ------- ---
WHERE DAYNAME(dt1) LIKE '%a%y' 0001-01-01 Monday 6
ORDER BY dt1; 1996-04-22 Monday 6
1996-08-15 Thursday 8
Figure 369, DAYNAME function example
SELECT dt1 ANSWER
,DAYOFWEEK(dt1) AS dwk =========================
,DAYNAME(dt1) AS dnm DT1 DWK DNM
FROM scalar ---------- --- --------
ORDER BY dwk 0001-01-01 2 Monday
,dnm; 1996-04-22 2 Monday
1996-08-15 5 Thursday
Figure 370, DAYOFWEEK function example
WITH ANSWER
temp1 (n) AS ========================
(VALUES (0) DATE DAY W D WI I
UNION ALL ---------- --- -- - -- -
SELECT n+1 1999-12-25 Sat 52 7 51 6
FROM temp1 1999-12-26 Sun 53 1 51 7
WHERE n < 9), 1999-12-27 Mon 53 2 52 1
temp2 (dt1) AS 1999-12-28 Tue 53 3 52 2
(VALUES(DATE('1999-12-25')) 1999-12-29 Wed 53 4 52 3
,(DATE('2000-12-24'))), 1999-12-30 Thu 53 5 52 4
temp3 (dt2) AS 1999-12-31 Fri 53 6 52 5
(SELECT dt1 + n DAYS 2000-01-01 Sat 1 7 52 6
FROM temp1 2000-01-02 Sun 2 1 52 7
,temp2) 2000-01-03 Mon 2 2 1 1
SELECT CHAR(dt2,ISO) AS date 2000-12-24 Sun 53 1 51 7
,SUBSTR(DAYNAME(dt2),1,3) AS day 2000-12-25 Mon 53 2 52 1
,WEEK(dt2) AS w 2000-12-26 Tue 53 3 52 2
,DAYOFWEEK(dt2) AS d 2000-12-27 Wed 53 4 52 3
,WEEK_ISO(dt2) AS wi 2000-12-28 Thu 53 5 52 4
,DAYOFWEEK_ISO(dt2) AS i 2000-12-29 Fri 53 6 52 5
FROM temp3 2000-12-30 Sat 53 7 52 6
ORDER BY 1; 2000-12-31 Sun 54 1 52 7
2001-01-01 Mon 1 2 1 1
2001-01-02 Tue 1 3 1 2
Figure 371, DAYOFWEEK_ISO function example
SELECT dt1 ANSWER
,DAYOFYEAR(dt1) AS dyr ===============
FROM scalar DT1 DYR
ORDER BY dyr; ---------- ---
0001-01-01 1
1996-04-22 113
1996-08-15 228
Figure 372, DAYOFYEAR function example
SELECT dt1 ANSWER
,DAYS(dt1) AS dy1 ==================
FROM scalar DT1 DY1
ORDER BY dy1 ---------- ------
,dt1; 0001-01-01 1
1996-04-22 728771
1996-08-15 728886
Figure 373, DAYS function example
Figure 374, DBPARTITIONNUM function syntax
SELECT DBPARTITIONNUM(id) AS dbnum ANSWER
FROM staff ======
WHERE id = 10; DBNUM
-----
0
Figure 375, DBPARTITIONNUM function example
Figure 376, DECFLOAT function syntax
ANSWER
======
SELECT DECFLOAT(+123.4) 123.4
,DECFLOAT(1.0 ,16) 1.0
,DECFLOAT(1.0000 ,16) 1.0000
,DECFLOAT(1.2e-3 ,34) 0.0011999999999999999
,DECFLOAT('1.2e-3' ,34) 0.0012
,DECFLOAT(-1E3 ,34) -1000
,DECFLOAT('-1E3' ,34) -1E+3
,DECFLOAT('12.5' ,16) 12.5
,DECFLOAT('12#5' ,16, '#') 12.5
FROM sysibm.sysdummy1;
Figure 377, DECFLOAT function example
Figure 378, DECIMAL function syntax
WITH temp1(n1,n2,c1,c2) AS ANSWER
(VALUES (123 ==========================
,1E2 DEC1 DEC2 DEC3 DEC4
,'123.4' ----- ------ ------ ------
,'567$8')) 123. 100.0 123.4 567.8
SELECT DEC(n1,3) AS dec1
,DEC(n2,4,1) AS dec2
,DEC(c1,4,1) AS dec3
,DEC(c2,4,1,'$') AS dec4
FROM temp1;
Figure 379, DECIMAL function examples
SELECT firstnme ANSWER
,sex ===========================
,CASE sex FIRSTNME SEX SEX2 SEX3
WHEN 'F' THEN 'FEMALE' --------- --- ------ ------
WHEN 'M' THEN 'MALE' BRUCE M MALE MALE
ELSE '?' CHRISTINE F FEMALE FEMALE
END AS sex2
,DECODE(sex,'F','FEMALE','M','MALE','?') AS sex3
FROM employee
WHERE firstnme < 'D'
ORDER BY firstnme;
Figure 380, DECODE function example
Figure 381, DECRYPT function syntax
SELECT id
,name
,DECRYPT_CHAR(name2,'CLUELESS') AS name3
,GETHINT(name2) AS hint
,name2
FROM (SELECT id
,name
,ENCRYPT(name,'CLUELESS','MY BOSS') AS name2
FROM staff
WHERE id < 30
)AS xxx
ORDER BY id;
Figure 382, DECRYPT_CHAR function example
SELECT a.name AS n1 ANSWER
,SOUNDEX(a.name) AS s1 ==============================
,b.name AS n2 N1 S1 N2 S2 DF
,SOUNDEX(b.name) AS s2 ------- ---- --------- ---- --
,DIFFERENCE Sanders S536 Sneider S536 4
(a.name,b.name) AS df Sanders S536 Smith S530 3
FROM staff a Sanders S536 Lundquist L532 2
,staff b Sanders S536 Daniels D542 1
WHERE a.id = 10 Sanders S536 Molinare M456 1
AND b.id > 150 Sanders S536 Scoutten S350 1
AND b.id < 250 Sanders S536 Abrahams A165 0
ORDER BY df DESC Sanders S536 Kermisch K652 0
,n2 ASC; Sanders S536 Lu L000 0
Figure 383, DIFFERENCE function example
SELECT s1 ANSWER
,DIGITS(s1) AS ds1 =========================
,d1 S1 DS1 D1 DD1
,DIGITS(d1) AS dd1 ------ ----- ----- ---
FROM scalar; -2 00002 -2.4 024
0 00000 0.0 000
1 00001 1.8 018
Figure 384, DIGITS function examples
WITH temp1(c1,d1) AS ANSWER (output shortened)
(VALUES ('12345',12.4) ==================================
,('-23.5',1234) C1D D1D
,('1E+45',-234) ---------------- ----------------
,('-2e05',+2.4)) +1.23450000E+004 +1.24000000E+001
SELECT DOUBLE(c1) AS c1d -2.35000000E+001 +1.23400000E+003
,DOUBLE(d1) AS d1d +1.00000000E+045 -2.34000000E+002
FROM temp1; -2.00000000E+005 +2.40000000E+000
Figure 385, DOUBLE function examples
Figure 386, DECRYPT function syntax
SELECT id
,name
,ENCRYPT(name,'THAT IDIOT','MY BROTHER') AS name2
FROM staff
WHERE ID < 30
ORDER BY id;
Figure 387, ENCRYPT function example
WITH temp1(n1) AS ANSWER
(VALUES (0) ==============================
UNION ALL N1 E1 E2
SELECT n1 + 1 -- --------------------- -----
FROM temp1 0 +1.00000000000000E+0 1
WHERE n1 < 10) 1 +2.71828182845904E+0 2
SELECT n1 2 +7.38905609893065E+0 7
,EXP(n1) AS e1 3 +2.00855369231876E+1 20
,SMALLINT(EXP(n1)) AS e2 4 +5.45981500331442E+1 54
FROM temp1; 5 +1.48413159102576E+2 148
6 +4.03428793492735E+2 403
7 +1.09663315842845E+3 1096
8 +2.98095798704172E+3 2980
9 +8.10308392757538E+3 8103
10 +2.20264657948067E+4 22026
Figure 388, EXP function examples
SELECT d1 ANSWER (float output shortened)
,FLOOR(d1) AS d2 ===================================
,f1 D1 D2 F1 F2
,FLOOR(f1) AS f2 ----- ---- ---------- ----------
FROM scalar; -2.4 -3. -2.400E+0 -3.000E+0
0.0 +0. +0.000E+0 +0.000E+0
1.8 +1. +1.800E+0 +1.000E+0
Figure 389, FLOOR function examples
SELECT id
,GENERATE_UNIQUE() AS unique_val#1
,DEC(HEX(GENERATE_UNIQUE()),26) AS unique_val#2
FROM staff
WHERE id < 50
ORDER BY id; ANSWER
================= ===========================
ID UNIQUE_VAL#1 UNIQUE_VAL#2
-- -------------- ---------------------------
NOTE: 2ND FIELD => 10 20011017191648990521000000.
IS UNPRINTABLE. => 20 20011017191648990615000000.
30 20011017191648990642000000.
40 20011017191648990669000000.
Figure 390, GENERATE_UNIQUE function examples
SELECT CURRENT TIMESTAMP AS ts1
,TIMESTAMP(GENERATE_UNIQUE()) AS ts2
,TIMESTAMP(GENERATE_UNIQUE()) + CURRENT TIMEZONE AS ts3
FROM sysibm.sysdummy1;
ANSWER
================================
TS1: 2007-01-19-18.12.33.587000
TS2: 2007-01-19-22.12.28.434960
TS3: 2007-01-19-18.12.28.434953
Figure 391, Covert GENERATE_UNIQUE output to timestamp
SELECT u1
,SUBSTR(u1,20,1) CONCAT SUBSTR(u1,19,1) CONCAT
SUBSTR(u1,18,1) CONCAT SUBSTR(u1,17,1) CONCAT
SUBSTR(u1,16,1) CONCAT SUBSTR(u1,15,1) CONCAT
SUBSTR(u1,14,1) CONCAT SUBSTR(u1,13,1) CONCAT
SUBSTR(u1,12,1) CONCAT SUBSTR(u1,11,1) CONCAT
SUBSTR(u1,10,1) CONCAT SUBSTR(u1,09,1) CONCAT
SUBSTR(u1,08,1) CONCAT SUBSTR(u1,07,1) CONCAT
SUBSTR(u1,06,1) CONCAT SUBSTR(u1,05,1) CONCAT
SUBSTR(u1,04,1) CONCAT SUBSTR(u1,03,1) CONCAT
SUBSTR(u1,02,1) CONCAT SUBSTR(u1,01,1) AS U2
FROM (SELECT HEX(GENERATE_UNIQUE()) AS u1
FROM staff
WHERE id < 50) AS xxx
ORDER BY u2; ANSWER
================================================
U1 U2
-------------------------- --------------------
20000901131649119940000000 04991194613110900002
20000901131649119793000000 39791194613110900002
20000901131649119907000000 70991194613110900002
20000901131649119969000000 96991194613110900002
Figure 392, GENERATE_UNIQUE output, characters reversed to make pseudo-random
SELECT u1
,SUBSTR(reverse(CHAR(u1)),7,20) AS u2
FROM (SELECT HEX(GENERATE_UNIQUE()) AS u1
FROM STAFF
WHERE ID < 50) AS xxx
ORDER BY U2;
Figure 393, GENERATE_UNIQUE output, characters reversed using function
SELECT id
,name
,GETHINT(name2) AS hint
FROM (SELECT id
,name
,ENCRYPT(name,'THAT IDIOT','MY BROTHER') AS name2
FROM staff
WHERE id < 30 ANSWER
)AS xxx =====================
ORDER BY id; ID NAME HINT
-- ------- ----------
10 Sanders MY BROTHER
20 Pernal MY BROTHER
Figure 394, GETHINT function example
SELECT HASHEDVALUE(id) AS hvalue ANSWER
FROM staff ======
WHERE id = 10; HVALUE
------
0
Figure 395, HASHEDVALUE function example
WITH temp1(n1) AS ANSWER
(VALUES (-3) ===============================
UNION ALL S SHX DHX FHX
SELECT n1 + 1 -- ---- ------ ----------------
FROM temp1 -3 FDFF 00003D 00000000000008C0
WHERE n1 < 3) -2 FEFF 00002D 00000000000000C0
SELECT SMALLINT(n1) AS s -1 FFFF 00001D 000000000000F0BF
,HEX(SMALLINT(n1)) AS shx 0 0000 00000C 0000000000000000
,HEX(DEC(n1,4,0)) AS dhx 1 0100 00001C 000000000000F03F
,HEX(DOUBLE(n1)) AS fhx 2 0200 00002C 0000000000000040
FROM temp1; 3 0300 00003C 0000000000000840
Figure 396, HEX function examples, numeric data
SELECT c1 ANSWER
,HEX(c1) AS chx =======================================
,v1 C1 CHX V1 VHX
,HEX(v1) AS vhx ------ ------------ ------ ------------
FROM scalar; ABCDEF 414243444546 ABCDEF 414243444546
ABCD 414243442020 ABCD 41424344
AB 414220202020 AB 4142
Figure 397, HEX function examples, character & varchar
SELECT dt1 ANSWER
,HEX(dt1) AS dthx ===================================
,tm1 DT1 DTHX TM1 TMHX
,HEX(tm1) AS tmhx ---------- -------- -------- ------
FROM scalar; 1996-04-22 19960422 23:58:58 235858
1996-08-15 19960815 15:15:15 151515
0001-01-01 00010101 00:00:00 000000
Figure 398, HEX function examples, date & time
SELECT tm1 ANSWER
,HOUR(tm1) AS hr ============
FROM scalar TM1 HR
ORDER BY tm1; -------- --
00:00:00 0
15:15:15 15
23:58:58 23
Figure 399, HOUR function example
CREATE TABLE seq#
(ident_val INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY
,cur_ts TIMESTAMP NOT NULL
,PRIMARY KEY (ident_val));
COMMIT;
INSERT INTO seq# VALUES(DEFAULT,CURRENT TIMESTAMP);
ANSWER
WITH temp (idval) AS ======
(VALUES (IDENTITY_VAL_LOCAL())) IDVAL
SELECT * -----
FROM temp; 1.
Figure 400, IDENTITY_VAL_LOCAL function usage
Figure 401, INSERT function syntax
SELECT name ANSWER (4K output fields shortened)
,INSERT(name,3,2,'A') ===================================
,INSERT(name,3,2,'AB') NAME 2 3 4
,INSERT(name,3,2,'ABC') -------- ------- -------- ---------
FROM staff Sanders SaAers SaABers SaABCers
WHERE id < 40; Pernal PeAal PeABal PeABCal
Marenghi MaAnghi MaABnghi MaABCnghi
Figure 402, INSERT function examples
SELECT d1 ANSWER
,INTEGER(d1) ====================================
,INT('+123') D1 2 3 4 5
,INT('-123') ----- ----- ------ ------ ------
,INT(' 123 ') -2.4 -2 123 -123 123
FROM scalar; 0.0 0 123 -123 123
1.8 1 123 -123 123
Figure 403, INTEGER function examples
WITH temp1(dt1) AS ANSWER
(VALUES ('0001-01-01-00.00.00') =========================
,('1752-09-10-00.00.00') DT DY DJ
,('2007-06-03-00.00.00') ---------- ------ -------
,('2007-06-03-23.59.59')) 0001-01-01 1 1721426
SELECT DATE(dt1) AS dt 1752-09-10 639793 2361218
,DAYS(dt1) AS dy 2007-06-03 732830 2454255
,JULIAN_DAY(dt1) AS dj 2007-06-03 732830 2454255
FROM temp1;
Figure 404, JULIAN_DAY function example
SELECT bd
,JULIAN_DAY(bd)
,(1461 * (YEAR(bd) + 4800 + (MONTH(bd)-14)/12))/4
+( 367 * (MONTH(bd)- 2 - 12*((MONTH(bd)-14)/12)))/12
-( 3 * ((YEAR(bd) + 4900 + (MONTH(bd)-14)/12)/100))/4
+DAY(bd) - 32075
FROM (SELECT birthdate AS bd
FROM employee
WHERE midinit = 'R' ANSWER
) AS xxx ==========================
ORDER BY bd; BD 2 3
---------- ------- -------
1926-05-17 2424653 2424653
1936-03-28 2428256 2428256
1946-07-09 2432011 2432011
1955-04-12 2435210 2435210
Figure 405, JULIAN_DAY function examples
ANSWER
=============================
DT DJ1 DJ2
WITH temp1(dt1) AS ---------- ---------- -------
(VALUES ('2007-01-01') 2007-01-01 2006-12-19 2007001
,('2007-01-02') 2007-01-02 2006-12-20 2007002
,('2007-12-31')) 2007-12-31 2007-12-18 2007365
SELECT DATE(dt1) AS dt
,DATE(dt1) - 13 DAYS AS dj1
,YEAR(dt1) * 1000 + DAYOFYEAR(dt1) AS dj2
FROM temp1;
Figure 406, Julian Date outputs
SELECT name ANSWER
,LCASE(name) AS lname =========================
,UCASE(name) AS uname NAME LNAME UNAME
FROM staff ------- ------- -------
WHERE id < 30; Sanders sanders SANDERS
Pernal pernal PERNAL
Figure 407, LCASE function example
WITH temp1(c1) AS ANSWER
(VALUES (' ABC') ================
,(' ABC ') C1 C2 L2
,('ABC ')) ----- ----- --
SELECT c1 ABC AB 4
,LEFT(c1,4) AS c2 ABC ABC 4
,LENGTH(LEFT(c1,4)) AS l2 ABC ABC 4
FROM temp1;
Figure 408, LEFT function examples
SELECT LENGTH(d1) ANSWER
,LENGTH(f1) =======================
,LENGTH(s1) 1 2 3 4 5
,LENGTH(c1) --- --- --- --- ---
,LENGTH(RTRIM(c1)) 2 8 2 6 6
FROM scalar; 2 8 2 6 4
2 8 2 6 2
Figure 409, LENGTH function examples
WITH temp1(n1) AS ANSWER
(VALUES (1),(123),(1234) ===============================
,(12345),(123456)) N1 L1
SELECT n1 ------ -----------------------
,LOG(n1) AS l1 1 +0.00000000000000E+000
FROM temp1; 123 +4.81218435537241E+000
1234 +7.11801620446533E+000
12345 +9.42100640177928E+000
123456 +1.17236400962654E+001
Figure 410, LOG function example
Figure 411, LOCATE function syntax
WITH temp1 (c1) As ANSWER
(VALUES ('abcdÄ'),('Äbcd'),('AÄ'),('ÁÄ')) ====================
SELECT c1 C1 l1 l2 l3 l4 l5
,LOCATE('Ä',c1) AS "l1" ----- -- -- -- -- --
,LOCATE('Ä',c1,2) AS "l2" abcdÄ 5 5 5 5 5
,LOCATE('Ä',c1,OCTETS) AS "l3" Äbcd 1 0 1 1 0
,LOCATE('Ä',c1,CODEUNITS16) AS "l4" AÄ 2 2 2 2 2
,LOCATE('Ä',c1,2,CODEUNITS16) AS "l5" ÁÄ 3 3 3 2 2
FROM temp1;
Figure 412, LOCATE function examples
WITH temp1(n1) AS ANSWER
(VALUES (1),(123),(1234) ===============================
,(12345),(123456)) N1 L1
SELECT n1 ------ -----------------------
,LOG10(n1) AS l1 1 +0.00000000000000E+000
FROM temp1; 123 +2.08990511143939E+000
1234 +3.09131515969722E+000
12345 +4.09149109426795E+000
123456 +5.09151220162777E+000
Figure 413, LOG10 function example
WITH temp1(c1) AS ANSWER
(VALUES (' ABC') ================
,(' ABC ') C1 C2 L2
,('ABC ')) ----- ----- --
SELECT c1 ABC ABC 3
,LTRIM(c1) AS c2 ABC ABC 4
,LENGTH(LTRIM(c1)) AS l2 ABC ABC 5
FROM temp1;
Figure 414, LTRIM function example
VALUES MAX(5,8,4) ANSWER => 8
Figure 415, MAX scalar function
SELECT MAX(MAX(salary,years,comm)) ANSWER => 87654.50
FROM STAFF;
Figure 416, Sample Views used in Join Examples
SELECT ts1 ANSWER
,MICROSECOND(ts1) ======================================
FROM scalar TS1 2
ORDER BY ts1; -------------------------- -----------
0001-01-01-00.00.00.000000 0
1996-04-22-23.58.58.123456 123456
1996-08-15-15.15.15.151515 151515
Figure 417, MICROSECOND function example
SELECT ts1 ANSWER
,MIDNIGHT_SECONDS(ts1) ======================================
,HOUR(ts1)*3600 + TS1 2 3
MINUTE(ts1)*60 + -------------------------- ----- -----
SECOND(ts1) 0001-01-01-00.00.00.000000 0 0
FROM scalar 1996-04-22-23.58.58.123456 86338 86338
ORDER BY ts1; 1996-08-15-15.15.15.151515 54915 54915
Figure 418, MIDNIGHT_SECONDS function example
ANSWER
==============
MS TM
----- --------
WITH temp1 (ms) AS 0 00:00:00
(SELECT MIDNIGHT_SECONDS(ts1) 54915 15:15:15
FROM scalar 86338 23:58:58
)
SELECT ms
,SUBSTR(DIGITS(ms/3600 ),9) || ':' ||
SUBSTR(DIGITS((ms-((MS/3600)*3600))/60 ),9) || ':' ||
SUBSTR(DIGITS(ms-((MS/60)*60) ),9) AS tm
FROM temp1
ORDER BY 1;
Figure 419, Convert MIDNIGHT_SECONDS output back to a time value
VALUES MIN(5,8,4) ANSWER => 4
Figure 420, MIN scalar function
SELECT ts1 ANSWER
,MINUTE(ts1) ======================================
FROM scalar TS1 2
ORDER BY ts1; -------------------------- -----------
0001-01-01-00.00.00.000000 0
1996-04-22-23.58.58.123456 58
1996-08-15-15.15.15.151515 15
Figure 421, MINUTE function example
WITH temp1(n1,n2) AS ANSWER
(VALUES (-31,+11) =======================
UNION ALL N1 N2 DIV MD1 MD2
SELECT n1 + 13 --- --- --- --- ---
,n2 - 4 -31 11 -2 -9 -9
FROM temp1 -18 7 -2 -4 -4
WHERE n1 < 60 -5 3 -1 -2 -2
) 8 -1 -8 0 0
SELECT n1 21 -5 -4 1 1
,n2 34 -9 -3 7 7
,n1/n2 AS div 47 -13 -3 8 8
,n1-((n1/n2)*n2) AS md1 60 -17 -3 9 9
,MOD(n1,n2) AS md2
FROM temp1
ORDER BY 1;
Figure 422, MOD function example
SELECT dt1 ANSWER
,MONTH(dt1) =======================
,MONTHNAME(dt1) DT1 2 3
FROM scalar ---------- -- -------
ORDER BY dt1; 0001-01-01 1 January
1996-04-22 4 April
1996-08-15 8 August
Figure 423, MONTH and MONTHNAME functions example
WITH temp1 (n1,n2) AS
(VALUES (DECIMAL(1234,10) ANSWER
,DECIMAL(1234,10))) ========
SELECT n1 >> 1234.
,n2 >> 1234.
,n1 * n2 AS p1 >> 1522756.
,"*"(n1,n2) AS p2 >> 1522756.
,MULTIPLY_ALT(n1,n2) AS p3 >> 1522756.
FROM temp1;
Figure 424, Multiplying numbers - examples
<--MULTIPLY_ALT->
RESULT RESULT SCALE PRECSION
INPUT#1 INPUT#2 "*" OPERATOR MULTIPLY_ALT TRUNCATD TRUNCATD
========== ========== ============ ============ ======== =======
DEC(05,00) DEC(05,00) DEC(10,00) DEC(10,00) NO NO
DEC(10,05) DEC(11,03) DEC(21,08) DEC(21,08) NO NO
DEC(20,15) DEC(21,13) DEC(31,28) DEC(31,18) YES NO
DEC(26,23) DEC(10,01) DEC(31,24) DEC(31,19) YES NO
DEC(31,03) DEC(15,08) DEC(31,11) DEC(31,03) YES YES
Figure 425, Decimal multiplication - same output lengths
ANSWER
===========================
D1 D2
WITH temp1 (d1) AS -------------------- ------
(VALUES (DECFLOAT(1)) 1 1
,(DECFLOAT(1.0)) 1.0 1
,(DECFLOAT(1.00)) 1.00 1
,(DECFLOAT(1.000)) 1.000 1
,(DECFLOAT('12.3')) 12.3 12.3
,(DECFLOAT('12.30')) 12.30 12.3
,(DECFLOAT(1.2e4)) 12000 1.2E+4
,(DECFLOAT('1.2e4')) 1.2E+4 1.2E+4
,(DECFLOAT(1.2e-3)) 0.001200000000000000 0.0012
,(DECFLOAT('1.2e-3')) 0.0012 0.0012
)
SELECT d1
,NORMALIZE_DECFLOAT(d1) AS d2
FROM temp1;
Figure 426, NORMALIZE_DECFLOAT function examples
SELECT s1 ANSWER
,NULLIF(s1,0) =====================
,c1 S1 2 C1 4
,NULLIF(c1,'AB') --- --- ------ ------
FROM scalar -2 -2 ABCDEF ABCDEF
WHERE NULLIF(0,0) IS NULL; 0 - ABCD ABCD
1 1 AB -
Figure 427, NULLIF function examples
WITH temp1 (c1) AS (VALUES (CAST('ÁÉÌ' AS VARCHAR(10))))
SELECT c1 AS C1
,LENGTH(c1) AS LEN
,OCTET_LENGTH(c1) AS OCT ANSWER
,CHAR_LENGTH(c1,OCTETS) AS L08 =======================
,CHAR_LENGTH(c1,CODEUNITS16) AS L16 C1 LEN OCT L08 L16 L32
,CHAR_LENGTH(c1,CODEUNITS32) AS L32 --- --- --- --- --- ---
FROM temp1; ÁÉÌ 6 6 6 3 3
Figure 428, OCTET_LENGTH example
Figure 429, OVERLAY function syntax
WITH temp1 (txt) AS
(VALUES('abcded'),('addd'),('adq'))
SELECT txt
,OVERLAY(txt,'XX',3,1,OCTETS) AS "s3f1"
,OVERLAY(txt,'XX',2, OCTETS) AS "s2f0"
,OVERLAY(txt,'XX',1,1,OCTETS) AS "s1f1"
,OVERLAY(txt,'XX',2,2,OCTETS) AS "s2f2"
FROM temp1; ANSWER
==========================================
TXT s3f1 s2f0 s1f1 s2f2
------ -------- -------- -------- --------
abcded abXXded aXXcded XXbcded aXXded
addd adXXd aXXdd XXddd aXXd
adq adXX aXXq XXdq aXX
Figure 430, OVERLAY function example
SELECT PARTITION(id) AS pp ANSWER
FROM staff ======
WHERE id = 10; PP
--
0
Figure 431, PARTITION function example
Figure 432, POSITION function syntax
WITH temp1 (c1) As ANSWER
(VALUES ('Ä'),('aÄ'),('ÁÄ'),('ÁÁÄ')) ===============
SELECT c1 C1 p1 p2 p3 p4
,POSITION('Ä',c1,OCTETS) AS "p1" --- -- -- -- --
,POSITION('Ä',c1,CODEUNITS16) AS "p2" Ä 1 1 1 1
,POSITION('Ä',c1,CODEUNITS32) AS "p3" aÄ 2 2 2 2
,POSITION('Ä' IN c1 USING OCTETS) AS "p4" ÁÄ 3 2 2 3
FROM temp1; ÁÁÄ 5 3 3 5
Figure 433, POSITION function syntax
SELECT c1 ANSWER
,POSSTR(c1,' ') AS p1 ==================
,POSSTR(c1,'CD') AS p2 C1 P1 P2 P3
,POSSTR(c1,'cd') AS p3 ------ -- -- --
FROM scalar AB 3 0 0
ORDER BY 1; ABCD 5 3 0
ABCDEF 0 3 0
Figure 434, POSSTR function example
SELECT c1 ANSWER
,POSSTR(c1,' ') AS p1 ===========================
,LOCATE(' ',c1) AS l1 C1 P1 L1 P2 L2 P3 L3 L4
,POSSTR(c1,'CD') AS p2 ------ -- -- -- -- -- -- --
,LOCATE('CD',c1) AS l2 AB 3 3 0 0 0 0 0
,POSSTR(c1,'cd') AS p3 ABCD 5 5 3 3 0 0 4
,LOCATE('cd',c1) AS l3 ABCDEF 0 0 3 3 0 0 4
,LOCATE('D',c1,2) AS l4
FROM scalar
ORDER BY 1;
Figure 435, POSSTR vs. LOCATE functions
WITH temp1(n1) AS ANSWER
(VALUES (1),(10),(100)) ===============================
SELECT n1 N1 P1 P2 P3
,POWER(n1,1) AS p1 ------- ------- ------- -------
,POWER(n1,2) AS p2 1 1 1 1
,POWER(n1,3) AS p3 10 10 100 1000
FROM temp1; 100 100 10000 1000000
Figure 436, POWER function examples
ANSWER
WITH temp1 (d1, d2) AS ------------------------
(VALUES (+1.23, DECFLOAT(1.0)) 1.2
,(+1.23, DECFLOAT(1.00)) 1.23
,(-1.23, DECFLOAT(1.000)) -1.230
,(+123, DECFLOAT(9.8765)) 123.0000
,(+123, DECFLOAT(1E-3)) 123.000
,(+123, DECFLOAT(1E+3)) 123
,(SQRT(2), DECFLOAT(0.0)) 1.4
,(SQRT(2), DECFLOAT('1E-5')) 1.41421
,(SQRT(2), DECFLOAT( 1E-5 )) 1.414213562373095100000
)
SELECT QUANTIZE(d1,d2)
FROM temp1;
Figure 437, QUANTIZE function examples
ANSWER
WITH temp1 (d1) AS -----------------------
(VALUES (DECFLOAT('1E-5')) 0.00001
,(DECFLOAT( 1E-5 )) 0.000010000000000000001
)
SELECT d1
FROM temp1;
Figure 438, DECFLOAT conversion example
Figure 439, RAISE_ERROR function syntax
SELECT s1 ANSWER
,CASE ==============
WHEN s1 < 1 THEN s1 S1 S2
ELSE RAISE_ERROR('80001',c1) ------ ------
END AS s2 -2 -2
FROM scalar; 0 0
SQLSTATE=80001
Figure 440, RAISE_ERROR function example
WITH temp (num, ran) AS
(VALUES (INT(1)
,RAND(2))
UNION ALL
SELECT num + 1
,RAND()
FROM temp
WHERE num < 100000 ANSWER
) =============
SELECT COUNT(*) AS #rows ==> 100000
,COUNT(DISTINCT ran) AS #values ==> 31242
,DEC(AVG(ran),7,6) AS avg_ran ==> 0.499838
,DEC(STDDEV(ran),7,6) AS std_dev 0.288706
,DEC(MIN(ran),7,6) AS min_ran 0.000000
,DEC(MAX(ran),7,6) AS max_ran 1.000000
,DEC(MAX(ran),7,6) -
DEC(MIN(ran),7,6) AS range 1.000000
,DEC(VAR(ran),7,6) AS variance 0.083351
FROM temp;
Figure 441, Sample output from RAND function
SELECT deptno AS dno ANSWER
,RAND(0) AS ran ===========================
FROM department DNO RAN
WHERE deptno < 'E' --- ----------------------
ORDER BY 1; A00 +1.15970336008789E-003
B01 +2.35572374645222E-001
C01 +6.48152104251228E-001
D01 +7.43736075930052E-002
D11 +2.70241401409955E-001
D21 +3.60026856288339E-001
Figure 442, Make reproducible random numbers (use seed)
SELECT deptno AS dno ANSWER
,RAND() AS ran ===========================
FROM department DNO RAN
WHERE deptno < 'D' --- ----------------------
ORDER BY 1; A00 +2.55287331766717E-001
B01 +9.85290078432569E-001
C01 +3.18918424024171E-001
Figure 443, Make non-reproducible random numbers (no seed)
WITH Temp1 (col1, col2, col3) AS ANSWER
(VALUES (0 ===================
,SMALLINT(RAND(2)*35)*10 COL1 COL2 COL3
,DECIMAL(RAND()*10000,7,2)) ---- ---- -------
UNION ALL 0 0 9342.32
SELECT col1 + 1 1 250 8916.28
,SMALLINT(RAND()*35)*10 2 310 5430.76
,DECIMAL(RAND()*10000,7,2) 3 150 5996.88
FROM temp1 4 110 8066.34
WHERE col1 + 1 < 10 5 50 5589.77
) 6 130 8602.86
SELECT * 7 340 184.94
FROM temp1; 8 310 5441.14
9 70 9267.55
Figure 444, Use RAND to make sample data
WITH temp1 (col1,ran1,ran2) AS ANSWER
(VALUES (0 ===================
,RAND(2) COL#1 RAN#1 RAN#2
,RAND()+(RAND()/1E5) ) ----- ----- -----
UNION ALL 30000 19698 29998
SELECT col1 + 1
,RAND()
,RAND() +(RAND()/1E5)
FROM temp1
WHERE col1 + 1 < 30000
)
SELECT COUNT(*) AS col#1
,COUNT(DISTINCT ran1) AS ran#1
,COUNT(DISTINCT ran2) AS ran#2
FROM temp1;
Figure 445, Use RAND to make many distinct random values
SELECT id ANSWER
,name ============
FROM staff ID NAME
WHERE RAND() < 0.1 --- --------
ORDER BY id; 140 Fraye
190 Sneider
290 Quill
Figure 446, Randomly select 10% of matching rows
SELECT id ANSWER
,name ============
FROM (SELECT s2.* ID NAME
,ROW_NUMBER() OVER(ORDER BY r1) AS r2 --- --------
FROM (SELECT s1.* 10 Sanders
,RAND() AS r1 30 Marenghi
FROM staff s1 40 O'Brien
WHERE id <= 100 70 Rothman
)AS s2 100 Plotz
)as s3
WHERE r2 <= 5
ORDER BY id;
Figure 447, Select five random rows
UPDATE staff
SET salary = RAND()*10000
WHERE id < 50;
Figure 448, Use RAND to assign random salaries
ANSWERS
================================
SELECT n1 AS dec => 1234567890.123456789012345678901
,DOUBLE(n1) AS dbl => 1.23456789012346e+009
,REAL(n1) AS rel => 1.234568e+009
,INTEGER(n1) AS int => 1234567890
,BIGINT(n1) AS big => 1234567890
FROM (SELECT 1234567890.123456789012345678901 AS n1
FROM staff
WHERE id = 10) AS xxx;
Figure 449, REAL and other numeric function examples
Figure 450, REPEAT function syntax
SELECT id ANSWER
,CHAR(REPEAT(name,3),40) ===========================
FROM staff ID 2
WHERE id < 40 -- ------------------------
ORDER BY id; 10 SandersSandersSanders
20 PernalPernalPernal
30 MarenghiMarenghiMarenghi
Figure 451, REPEAT function example
Figure 452, REPLACE function syntax
SELECT c1 ANSWER
,REPLACE(c1,'AB','XY') AS r1 ======================
,REPLACE(c1,'BA','XY') AS r2 C1 R1 R2
FROM scalar; ------ ------ ------
ABCDEF XYCDEF ABCDEF
ABCD XYCD ABCD
AB XY AB
Figure 453, REPLACE function examples
SELECT c1 ANSWER
,REPLACE(REPLACE( ==============
REPLACE(REPLACE(c1, C1 R1
'AB','XY'),'ab','XY'), ------ ------
'Ab','XY'),'aB','XY') ABCDEF XYCDEF
FROM scalar; ABCD XYCD
AB XY
Figure 454, Nested REPLACE functions
SELECT id ANSWER
,salary =====================
,RID(staff) AS staff_rid ID SALARY STAFF_RID
FROM staff -- -------- ---------
WHERE id < 40 10 98357.50 100663300
ORDER BY id; 20 78171.25 100663301
30 77506.75 100663302
Figure 455, RID function example
Figure 456, RID_BIT function example – single table
Figure 457, RID_BIT function example – multiple tables
Figure 458, RID_BIT function example – select row to update
Figure 459, RID_BIT function example – update row
WITH temp1(c1) AS ANSWER
(VALUES (' ABC') ================
,(' ABC ') C1 C2 L2
,('ABC ')) ----- ----- --
SELECT c1 ABC ABC 4
,RIGHT(c1,4) AS c2 ABC ABC 4
,LENGTH(RIGHT(c1,4)) as l2 ABC BC 4
FROM temp1;
Figure 460, RIGHT function examples
ANSWER
===============================================
D1 P2 P1 P0 N1 N2
------- ------- ------- ------- ------- -------
WITH temp1(d1) AS 123.400 123.400 123.400 123.000 120.000 100.000
(VALUES (123.400) 23.450 23.450 23.400 23.000 20.000 0.000
,( 23.450) 3.456 3.460 3.500 3.000 0.000 0.000
,( 3.456) 0.056 0.060 0.100 0.000 0.000 0.000
,( .056))
SELECT d1
,DEC(ROUND(d1,+2),6,3) AS p2
,DEC(ROUND(d1,+1),6,3) AS p1
,DEC(ROUND(d1,+0),6,3) AS p0
,DEC(ROUND(d1,-1),6,3) AS n1
,DEC(ROUND(d1,-2),6,3) AS n2
FROM temp1;
Figure 461, ROUND function examples
SELECT c1 ANSWER
,RTRIM(c1) AS r1 ======================
,LENGTH(c1) AS r2 C1 R1 R2 R3
,LENGTH(RTRIM(c1)) AS r3 ------ ------ -- --
FROM scalar; ABCDEF ABCDEF 6 6
ABCD ABCD 6 4
AB AB 6 2
Figure 462, RTRIM function example
SELECT d1 ANSWER (float output shortened)
,SIGN(d1) =========================================
,f1 D1 2 F1 4
,SIGN(f1) ----- ---------- ---------- ----------
FROM scalar; -2.4 -1.000E+0 -2.400E+0 -1.000E+0
0.0 +0.000E+0 +0.000E+0 +0.000E+0
1.8 +1.000E+0 +1.800E+0 +1.000E+0
Figure 463, SIGN function examples
WITH temp1(n1) AS ANSWER
(VALUES (0) =======================
UNION ALL N1 RAN SIN TAN
SELECT n1 + 10 -- ----- ----- -----
FROM temp1 0 0.000 0.000 0.000
WHERE n1 < 80) 10 0.174 0.173 0.176
SELECT n1 20 0.349 0.342 0.363
,DEC(RADIANS(n1),4,3) AS ran 30 0.523 0.500 0.577
,DEC(SIN(RADIANS(n1)),4,3) AS sin 40 0.698 0.642 0.839
,DEC(TAN(RADIANS(n1)),4,3) AS tan 50 0.872 0.766 1.191
FROM temp1; 60 1.047 0.866 1.732
70 1.221 0.939 2.747
80 1.396 0.984 5.671
Figure 464, SIN function example
SELECT d1 ANSWER
,SMALLINT(d1) ==================================
,SMALLINT('+123') D1 2 3 4 5
,SMALLINT('-123') ----- ------ ------ ------ ------
,SMALLINT(' 123 ') -2.4 -2 123 -123 123
FROM scalar; 0.0 0 123 -123 123
1.8 1 123 -123 123
Figure 465, SMALLINT function examples
SELECT a.name AS n1 ANSWER
,SOUNDEX(a.name) AS s1 ==============================
,b.name AS n2 N1 S1 N2 S2 DF
,SOUNDEX(b.name) AS s2 ------- ---- --------- ---- --
,DIFFERENCE Sanders S536 Sneider S536 4
(a.name,b.name) AS df Sanders S536 Smith S530 3
FROM staff a Sanders S536 Lundquist L532 2
,staff b Sanders S536 Daniels D542 1
WHERE a.id = 10 Sanders S536 Molinare M456 1
AND b.id > 150 Sanders S536 Scoutten S350 1
AND b.id < 250 Sanders S536 Abrahams A165 0
ORDER BY df DESC Sanders S536 Kermisch K652 0
,n2 ASC; Sanders S536 Lu L000 0
Figure 466, SOUNDEX function example
WITH temp1(n1) AS ANSWER
(VALUES (1),(2),(3)) ==================
SELECT n1 N1 S1 S2 S3
,SPACE(n1) AS s1 -- ---- -- ----
,LENGTH(SPACE(n1)) AS s2 1 1 X
,SPACE(n1) || 'X' AS s3 2 2 X
FROM temp1; 3 3 X
Figure 467, SPACE function examples
WITH temp1(n1) AS ANSWER
(VALUES (0.5),(0.0) ============
,(1.0),(2.0)) N1 S1
SELECT DEC(n1,4,3) AS n1 ----- -----
,DEC(SQRT(n1),4,3) AS s1 0.500 0.707
FROM temp1; 0.000 0.000
1.000 1.000
2.000 1.414
Figure 468, SQRT function example
Figure 469, STRIP function syntax
WITH temp1(c1) AS ANSWER
(VALUES (' ABC') =============================
,(' ABC ') C1 C2 L2 C3 L3 C4
,('ABC ')) ----- ----- -- ----- -- -----
ABC ABC 3 ABC 3 ABC
SELECT c1 AS C1 ABC ABC 3 ABC 4 ABC
,STRIP(c1) AS C2 ABC ABC 3 ABC 5 BC
,LENGTH(STRIP(c1)) AS L2
,STRIP(c1,LEADING) AS C3
,LENGTH(STRIP(c1,LEADING)) AS L3
,STRIP(c1,LEADING,'A') AS C4
FROM temp1;
Figure 470, STRIP function example
Figure 471, SUBSTR function syntax
WITH temp1 (len, dat1) AS ANSWER
(VALUES ( 6,'123456789') =========================
,( 4,'12345' ) LEN DAT1 LDAT SUBDAT
,( 16,'123' ) --- --------- ---- ------
) 6 123456789 9 123456
SELECT len 4 12345 5 1234
,dat1
,LENGTH(dat1) AS ldat
,SUBSTR(dat1,1,len) AS subdat
FROM temp1;
Figure 472, SUBSTR function - error because length parm too long
WITH temp1 (len, dat1) AS ANSWER
(VALUES ( 6,'123456789') =========================
,( 4,'12345' ) LEN DAT1 LDAT SUBDAT
,( 16,'123' ) --- --------- ---- ------
) 6 123456789 9 123456
SELECT len 4 12345 5 1234
,dat1 16 123 3 123
,LENGTH(dat1) AS ldat
,SUBSTR(dat1,1,CASE
WHEN len < LENGTH(dat1) THEN len
ELSE LENGTH(dat1)
END ) AS subdat
FROM temp1;
Figure 473, SUBSTR function - avoid error using CASE (see previous)
SELECT name ANSWER
,LENGTH(name) AS len ===========================
,SUBSTR(name,5) AS s1 NAME LEN S1 L1 S2 L2
,LENGTH(SUBSTR(name,5)) AS l1 -------- --- ---- -- --- --
,SUBSTR(name,5,3) AS s2 Sanders 7 ers 3 ers 3
,LENGTH(SUBSTR(name,5,3)) AS l2 Pernal 6 al 2 al 3
FROM staff Marenghi 8 nghi 4 ngh 3
WHERE id < 60; O'Brien 7 ien 3 ien 3
Hanes 5 s 1 s 3
Figure 474, SUBSTR function - fixed length output if third parm. used
SELECT a.id ANSWER
,a.dept ==========================
,a.salary ID DEPT SALARY DEPTSAL
,b.deptsal -- ---- -------- ---------
FROM staff a 10 20 98357.50 254286.10
,TABLE 20 20 78171.25 254286.10
(SELECT b.dept 30 38 77506.75 302285.55
,SUM(b.salary) AS deptsal
FROM staff b
WHERE b.dept = a.dept
GROUP BY b.dept
)AS b
WHERE a.id < 40
ORDER BY a.id;
Figure 475, Fullselect with external table reference
CREATE ALIAS emp1 FOR employee; ANSWER
CREATE ALIAS emp2 FOR emp1; =======================
TABSCHEMA TABNAME CARD
SELECT tabschema --------- -------- ----
,tabname graeme employee -1
,card
FROM syscat.tables
WHERE tabname = TABLE_NAME('emp2','graeme');
Figure 476, TABLE_NAME function example
CREATE VIEW fred1 (c1, c2, c3) ANSWER
AS VALUES (11, 'AAA', 'BBB'); ===========================
TAB_SCH TAB_NME
CREATE ALIAS fred2 FOR fred1; -------- ------------------
CREATE ALIAS fred3 FOR fred2; graeme fred1
graeme xxxxx
DROP VIEW fred1;
WITH temp1 (tab_sch, tab_nme) AS
(VALUES (TABLE_SCHEMA('fred3','graeme'),TABLE_NAME('fred3')),
(TABLE_SCHEMA('xxxxx') ,TABLE_NAME('xxxxx','xxx')))
SELECT *
FROM temp1;
Figure 477, TABLE_SCHEMA and TABLE_NAME functions example
SELECT TIMESTAMP('1997-01-11-22.44.55.000000')
,TIMESTAMP('1997-01-11-22.44.55.000')
,TIMESTAMP('1997-01-11-22.44.55')
,TIMESTAMP('19970111224455')
,TIMESTAMP('1997-01-11','22.44.55')
FROM staff
WHERE id = 10;
Figure 478, TIMESTAMP function examples
WITH temp1 (ts1) AS
(VALUES ('1999-12-31 23:59:59')
,('2002-10-30 11:22:33')
)
SELECT ts1
,TIMESTAMP_FORMAT(ts1,'YYYY-MM-DD HH24:MI:SS') AS ts2
FROM temp1
ORDER BY ts1; ANSWER
===============================================
TS1 TS2
------------------- --------------------------
1999-12-31 23:59:59 1999-12-31-23.59.59.000000
2002-10-30 11:22:33 2002-10-30-11.22.33.000000
Figure 479, TIMESTAMP_FORMAT function example
SELECT tm1 ANSWER
,TIMESTAMP_ISO(tm1) ===================================
FROM scalar; TM1 2
-------- --------------------------
23:58:58 2000-09-01-23.58.58.000000
15:15:15 2000-09-01-15.15.15.000000
00:00:00 2000-09-01-00.00.00.000000
Figure 480, TIMESTAMP_ISO function example
WITH
temp1 (ts1,ts2) AS
(VALUES ('1996-03-01-00.00.01','1995-03-01-00.00.00')
,('1996-03-01-00.00.00','1995-03-01-00.00.01')),
temp2 (ts1,ts2) AS
(SELECT TIMESTAMP(ts1)
,TIMESTAMP(ts2)
FROM temp1),
temp3 (ts1,ts2,df) AS
(SELECT ts1
,ts2
,CHAR(TS1 - TS2) AS df ANSWER
FROM temp2) =============================
SELECT df DF DIF DYS
,TIMESTAMPDIFF(16,df) AS dif --------------------- --- ---
,DAYS(ts1) - DAYS(ts2) AS dys 00010000000001.000000 365 366
FROM temp3; 00001130235959.000000 360 366
Figure 481, TIMESTAMPDIFF function example
CREATE FUNCTION ts_diff_works(in_hi TIMESTAMP,in_lo TIMESTAMP)
RETURNS BIGINT
RETURN (BIGINT(DAYS(in_hi)) * 86400000000
+ BIGINT(MIDNIGHT_SECONDS(in_hi)) * 1000000
+ BIGINT(MICROSECOND(in_hi)))
-(BIGINT(DAYS(in_lo)) * 86400000000
+ BIGINT(MIDNIGHT_SECONDS(in_lo)) * 1000000
+ BIGINT(MICROSECOND(in_lo)));
Figure 482, Function to get difference between two timestamps
ANSWER
WITH temp1 (d1, d2) AS ======
(VALUES (DECFLOAT(+1.0), DECFLOAT(+1.0)) 0
,(DECFLOAT(+1.0), DECFLOAT(+1.00)) 1
,(DECFLOAT(-1.0), DECFLOAT(-1.00)) -1
,(DECFLOAT(+0.0), DECFLOAT(+0.00)) 1
,(DECFLOAT(-0.0), DECFLOAT(-0.00)) 1
,(DECFLOAT(1234), +infinity) -1
,(+infinity, +infinity) 0
,(+infinity, -infinity) 1
,(DECFLOAT(1234), -NaN) 1
)
SELECT TOTALORDER(d1,d2)
FROM temp1;
Figure 483, TOTALORDER function example
Figure 484, TRANSLATE function syntax
ANS. NOTES
==== =================
SELECT 'abcd' ==> abcd No change
,TRANSLATE('abcd') ==> ABCD Make upper case
,TRANSLATE('abcd','','a') ==> bcd 'a'=>' '
,TRANSLATE('abcd','A','A') abcd 'A'=>'A'
,TRANSLATE('abcd','A','a') Abcd 'a'=>'A'
,TRANSLATE('abcd','A','ab') A cd 'a'=>'A','b'=>' '
,TRANSLATE('abcd','A','ab',' ') A cd 'a'=>'A','b'=>' '
,TRANSLATE('abcd','A','ab','z') Azcd 'a'=>'A','b'=>'z'
,TRANSLATE('abcd','AB','a') Abcd 'a'=>'A'
FROM staff
WHERE id = 10;
Figure 485, TRANSLATE function examples
ANSWER
======
SELECT c1 ==> ABCD
,REPLACE(c1,'AB','XY') ==> XYCD
,REPLACE(c1,'BA','XY') ==> ABCD
,TRANSLATE(c1,'XY','AB') XYCD
,TRANSLATE(c1,'XY','BA') YXCD
FROM scalar
WHERE c1 = 'ABCD';
Figure 486, REPLACE vs. TRANSLATE
ANSWER
===============================================
D1 POS2 POS1 ZERO NEG1 NEG2
------- ------- ------- ------- ------- -------
WITH temp1(d1) AS 123.400 123.400 123.400 123.000 120.000 100.000
(VALUES (123.400) 23.450 23.440 23.400 23.000 20.000 0.000
,( 23.450) 3.456 3.450 3.400 3.000 0.000 0.000
,( 3.456) 0.056 0.050 0.000 0.000 0.000 0.000
,( .056))
SELECT d1
,DEC(TRUNC(d1,+2),6,3) AS pos2
,DEC(TRUNC(d1,+1),6,3) AS pos1
,DEC(TRUNC(d1,+0),6,3) AS zero
,DEC(TRUNC(d1,-1),6,3) AS neg1
,DEC(TRUNC(d1,-2),6,3) AS neg2
FROM temp1
ORDER BY 1 DESC;
Figure 487, TRUNCATE function examples
SELECT name ANSWER
,LCASE(name) AS lname =========================
,UCASE(name) AS uname NAME LNAME UNAME
FROM staff ------- ------- -------
WHERE id < 30; Sanders sanders SANDERS
Pernal pernal PERNAL
Figure 488, UCASE function example
SELECT c1 ANSWER
,LENGTH(c1) AS l1 ========================
,VARCHAR(c1) AS v2 C1 L1 V2 L2 V3
,LENGTH(VARCHAR(c1)) AS l2 ------ -- ------ -- ----
,VARCHAR(c1,4) AS v3 ABCDEF 6 ABCDEF 6 ABCD
FROM scalar; ABCD 6 ABCD 6 ABCD
AB 6 AB 6 AB
Figure 489, VARCHAR function examples
WITH temp1 (ts1) AS
(VALUES (TIMESTAMP('1999-12-31-23.59.59'))
,(TIMESTAMP('2002-10-30-11.22.33'))
)
SELECT ts1
,VARCHAR_FORMAT(ts1,'YYYY-MM-DD HH24:MI:SS') AS ts2
FROM temp1
ORDER BY ts1; ANSWER
==============================================
TS1 TS2
-------------------------- -------------------
1999-12-31-23.59.59.000000 1999-12-31 23:59:59
2002-10-30-11.22.33.000000 2002-10-30 11:22:33
Figure 490, VARCHAR_FORMAT function example
SELECT WEEK(DATE('2000-01-01')) AS w1 ANSWER
,WEEK(DATE('2000-01-02')) AS w2 ==================
,WEEK(DATE('2001-01-02')) AS w3 W1 W2 W3 W4 W5
,WEEK(DATE('2000-12-31')) AS w4 -- -- -- -- --
,WEEK(DATE('2040-12-31')) AS w5 1 2 1 54 53
FROM sysibm.sysdummy1;
Figure 491, WEEK function examples
WITH ANSWER
temp1 (n) AS ==========================
(VALUES (0) DTE DY WK DY WI DI
UNION ALL ---------- --- -- -- -- --
SELECT n+1 1998-12-27 Sun 53 1 52 7
FROM temp1 1998-12-28 Mon 53 2 53 1
WHERE n < 10), 1998-12-29 Tue 53 3 53 2
temp2 (dt2) AS 1998-12-30 Wed 53 4 53 3
(SELECT DATE('1998-12-27') + y.n YEARS 1998-12-31 Thu 53 5 53 4
+ d.n DAYS 1999-01-01 Fri 1 6 53 5
FROM temp1 y 1999-01-02 Sat 1 7 53 6
,temp1 d 1999-01-03 Sun 2 1 53 7
WHERE y.n IN (0,2)) 1999-01-04 Mon 2 2 1 1
SELECT CHAR(dt2,ISO) dte 1999-01-05 Tue 2 3 1 2
,SUBSTR(DAYNAME(dt2),1,3) dy 1999-01-06 Wed 2 4 1 3
,WEEK(dt2) wk 2000-12-27 Wed 53 4 52 3
,DAYOFWEEK(dt2) dy 2000-12-28 Thu 53 5 52 4
,WEEK_ISO(dt2) wi 2000-12-29 Fri 53 6 52 5
,DAYOFWEEK_ISO(dt2) di 2000-12-30 Sat 53 7 52 6
FROM temp2 2000-12-31 Sun 54 1 52 7
ORDER BY 1; 2001-01-01 Mon 1 2 1 1
2001-01-02 Tue 1 3 1 2
2001-01-03 Wed 1 4 1 3
2001-01-04 Thu 1 5 1 4
2001-01-05 Fri 1 6 1 5
2001-01-06 Sat 1 7 1 6
Figure 492, WEEK_ISO function example
SELECT dt1 ANSWER
,YEAR(dt1) AS yr ======================
,WEEK(dt1) AS wk DT1 YR WK
FROM scalar; ---------- ---- ----
1996-04-22 1996 17
1996-08-15 1996 33
0001-01-01 1 1
Figure 493, YEAR and WEEK functions example
SELECT id ANSWER
,salary =============================
,"+"(salary) AS s2 ID SALARY S2 S3
,"+"(salary,id) AS s3 -- -------- -------- --------
FROM staff 10 98357.50 98357.50 98367.50
WHERE id < 40 20 78171.25 78171.25 78191.25
ORDER BY id; 30 77506.75 77506.75 77536.75
Figure 494, PLUS function examples
SELECT empno
,CHAR(birthdate,ISO) AS bdate1
,CHAR(birthdate + 1 YEAR,ISO) AS bdate2
,CHAR("+"(birthdate,DEC(00010000,8)),ISO) AS bdate3
,CHAR("+"(birthdate,DOUBLE(1),SMALLINT(1)),ISO) AS bdate4
FROM employee
WHERE empno < '000040'
ORDER BY empno; ANSWER
==================================================
EMPNO BDATE1 BDATE2 BDATE3 BDATE4
------ ---------- ---------- ---------- ----------
000010 1933-08-24 1934-08-24 1934-08-24 1934-08-24
000020 1948-02-02 1949-02-02 1949-02-02 1949-02-02
000030 1941-05-11 1942-05-11 1942-05-11 1942-05-11
Figure 495, Adding one year to date value
SELECT id ANSWER
,salary ==============================
,"-"(salary) AS s2 ID SALARY S2 S3
,"-"(salary,id) AS s3 -- -------- --------- --------
FROM staff 10 98357.50 -98357.50 98347.50
WHERE id < 40 20 78171.25 -78171.25 78151.25
ORDER BY id; 30 77506.75 -77506.75 77476.75
Figure 496, MINUS function examples
SELECT id ANSWER
,salary =================================
,salary * id AS s2 ID SALARY S2 S3
,"*"(salary,id) AS s3 -- -------- ---------- ----------
FROM staff 10 98357.50 983575.00 983575.00
WHERE id < 40 20 78171.25 1563425.00 1563425.00
ORDER BY id; 30 77506.75 2325202.50 2325202.50
Figure 497, MULTIPLY function examples
SELECT id ANSWER
,salary ===========================
,salary / id AS s2 ID SALARY S2 S3
,"/"(salary,id) AS s3 -- -------- ------- -------
FROM staff 10 98357.50 9835.75 9835.75
WHERE id < 40 20 78171.25 3908.56 3908.56
ORDER BY id; 30 77506.75 2583.55 2583.55
Figure 498, DIVIDE function examples
SELECT id ANSWER
,name || 'Z' AS n1 ===========================
,name CONCAT 'Z' AS n2 ID N1 N2 N3 N4
,"||"(name,'Z') As n3 --- ----- ----- ----- -----
,CONCAT(name,'Z') As n4 110 NganZ NganZ NganZ NganZ
FROM staff 210 LuZ LuZ LuZ LuZ
WHERE LENGTH(name) < 5 270 LeaZ LeaZ LeaZ LeaZ
ORDER BY id;
Figure 499, CONCAT function examples
Figure 500, Sourced function syntax
CREATE FUNCTION digi_int (SMALLINT)
RETURNS CHAR(5)
SOURCE SYSIBM.DIGITS(SMALLINT);
Figure 501, Create sourced function
SELECT id AS ID ANSWER
,DIGITS(id) AS I2 ==============
,digi_int(id) AS I3 ID I2 I3
FROM staff -- ----- -----
WHERE id < 40 10 00010 00010
ORDER BY id; 20 00020 00020
30 00030 00030
Figure 502, Using sourced function - works
SELECT id ANSWER
,digi_int(INT(id)) =======
FROM staff
WHERE id < 50;
Figure 503, Using sourced function - fails
CREATE DISTINCT TYPE us_dollars AS DEC(7,2) WITH COMPARISONS;
CREATE TABLE customers
(ID SMALLINT NOT NULL
,balance us_dollars NOT NULL);
ANSWER
INSERT INTO customers VALUES (1 ,111.11),(2 ,222.22); ==========
ID balance
SELECT * -- -------
FROM customers 1 111.11
ORDER BY ID; 2 222.22
Figure 504, Create distinct type and test table
SELECT id ANSWER
,balance * 10 =======
FROM customers
ORDER BY id;
Figure 505, Do multiply - fails
CREATE FUNCTION "*" (us_dollars,INT)
RETURNS us_dollars
SOURCE SYSIBM."*"(DECIMAL,INT);
Figure 506, Create sourced function
SELECT id ANSWER
,balance * 10 AS newbal ==========
FROM customers ID NEWBAL
ORDER BY id; -- -------
1 1111.10
2 2222.20
Figure 507, Do multiply - works
SELECT id ANSWER
,"*"(balance,10) AS newbal ==========
FROM customers ID NEWBAL
ORDER BY id; -- -------
1 1111.10
2 2222.20
Figure 508, Do multiply - works
Figure 509, Scalar and Table function syntax
CREATE FUNCTION Test() RETURNS CHAR(5) RETURN 'abcde';
Figure 510, Function returns nullable, but never null, value
CREATE FUNCTION returns_zero() RETURNS SMALLINT RETURN 0;
ANSWER
SELECT id AS id ======
,returns_zero() AS zz ID ZZ
FROM staff -- --
WHERE id = 10; 10 0
Figure 511, Simple function usage
CREATE FUNCTION calc(inval SMALLINT) RETURNS INT RETURN inval * 10;
CREATE FUNCTION calc(inval INTEGER) RETURNS INT RETURN inval * 5;
SELECT id AS id ANSWER
,calc(SMALLINT(id)) AS c1 ==========
,calc(INTEGER (id)) AS C2 ID C1 C2
FROM staff -- --- ---
WHERE id < 30 10 100 50
ORDER BY id; 20 200 100
DROP FUNCTION calc(SMALLINT);
DROP FUNCTION calc(INTEGER);
Figure 512, Two functions with same name
CREATE FUNCTION rnd(inval INT)
RETURNS SMALLINT
NOT DETERMINISTIC
RETURN RAND() * 50; ANSWER
======
SELECT id AS id ID RND
,rnd(1) AS RND -- ---
FROM staff 10 37
WHERE id < 40 20 8
ORDER BY id; 30 42
Figure 513, Not deterministic function
CREATE FUNCTION get_sal(inval SMALLINT)
RETURNS DECIMAL(7,2)
RETURN SELECT salary
FROM staff
WHERE id = inval; ANSWER
===========
SELECT id AS id ID SALARY
,get_sal(id) AS salary -- --------
FROM staff 10 98357.50
WHERE id < 40 20 78171.25
ORDER BY id; 30 77506.75
Figure 514, Function using query
CREATE FUNCTION max_sal(inval SMALLINT)
RETURNS DECIMAL(7,2)
RETURN WITH
ddd (max_sal) AS
(SELECT MAX(S2.salary)
FROM staff S1
,staff S2
WHERE S1.id = inval
AND S1.dept = s2.dept)
,yyy (max_sal) AS
(SELECT MAX(S2.salary)
FROM staff S1
,staff S2
WHERE S1.id = inval
AND S1.years = s2.years)
SELECT CASE
WHEN ddd.max_sal > yyy.max_sal
THEN ddd.max_sal
ELSE yyy.max_sal
END
FROM ddd, yyy;
ANSWER
SELECT id AS id ====================
,salary AS SAL1 ID SAL1 SAL2
,max_sal(id) AS SAL2 -- -------- --------
FROM staff 10 98357.50 98357.50
WHERE id < 40 20 78171.25 98357.50
ORDER BY id; 30 77506.75 79260.25
Figure 515, Function using common table expression
CREATE FUNCTION remove_e(instr VARCHAR(50))
RETURNS VARCHAR(50)
RETURN replace(instr,'e','');
UPDATE staff
SET name = remove_e(name)
WHERE id < 40;
Figure 516, Function used in update
--#SET DELIMITER ! IMPORTANT
============
CREATE FUNCTION reverse(instr VARCHAR(50)) This example
RETURNS VARCHAR(50) uses an "!"
BEGIN ATOMIC as the stmt
DECLARE outstr VARCHAR(50) DEFAULT ''; delimiter.
DECLARE curbyte SMALLINT DEFAULT 0;
SET curbyte = LENGTH(RTRIM(instr));
WHILE curbyte >= 1 DO
SET outstr = outstr || SUBSTR(instr,curbyte,1);
SET curbyte = curbyte - 1;
END WHILE;
RETURN outstr;
END!
ANSWER
SELECT id AS id ====================
,name AS name1 ID NAME1 NAME2
,reverse(name) AS name2 -- -------- -------
FROM staff 10 Sanders srednaS
WHERE id < 40 20 Pernal lanreP
ORDER BY id! 30 Marenghi ihgneraM
Figure 517, Function using compound SQL
--#SET DELIMITER ! IMPORTANT
============
CREATE FUNCTION check_len(instr VARCHAR(50)) This example
RETURNS SMALLINT uses an "!"
BEGIN ATOMIC as the stmt
IF instr IS NULL THEN delimiter.
RETURN NULL;
END IF;
IF length(instr) < 6 THEN
SIGNAL SQLSTATE '75001'
SET MESSAGE_TEXT = 'Input string is < 6';
ELSEIF length(instr) < 7 THEN
RETURN -1;
END IF;
RETURN length(instr); ANSWER
END! =================
ID NAME1 NAME2
SELECT id AS id -- -------- -----
,name AS name1 10 Sanders 7
,check_len(name) AS name2 20 Pernal -1
FROM staff 30 Marenghi 8
WHERE id < 60 40 O'Brien 7
ORDER BY id!
Figure 518, Function with error checking logic
CREATE FUNCTION get_staff()
RETURNS TABLE (ID SMALLINT
,name VARCHAR(9)
,YR SMALLINT)
RETURN SELECT id
,name
,years ANSWER
FROM staff; ==============
ID NAME YR
SELECT * -- -------- --
FROM TABLE(get_staff()) AS s 10 Sanders 7
WHERE id < 40 20 Pernal 8
ORDER BY id; 30 Marenghi 5
Figure 519, Simple table function
Figure 520, Table function usage - syntax
CREATE FUNCTION get_st(inval INTEGER)
RETURNS TABLE (id SMALLINT
,name VARCHAR(9)
,yr SMALLINT)
RETURN SELECT id
,name
,years
FROM staff ANSWER
WHERE id = inval; ==============
ID NNN YY
SELECT * -- -------- --
FROM TABLE(get_st(30)) AS sss (id, nnn, yy); 30 Marenghi 5
Figure 521, Table function with parameters
CREATE FUNCTION make_data()
RETURNS TABLE (KY SMALLINT
,DAT CHAR(5))
RETURN WITH temp1 (k#) AS (VALUES (1),(2),(3)) ANSWER
SELECT k# ========
,DIGITS(SMALLINT(k#)) KY DAT
FROM temp1; -- -----
1 00001
SELECT * 2 00002
FROM TABLE(make_data()) AS ttt; 3 00003
Figure 522, Table function that creates data
CREATE FUNCTION staff_list(lo_key INTEGER IMPORTANT
,lo_sal INTEGER) ============
RETURNS TABLE (id SMALLINT This example
,salary DECIMAL(7,2) uses an "!"
,max_sal DECIMAL(7,2) as the stmt
,id_max SMALLINT) delimiter.
LANGUAGE SQL
READS SQL DATA
EXTERNAL ACTION
DETERMINISTIC
BEGIN ATOMIC
DECLARE hold_sal DECIMAL(7,2) DEFAULT 0;
DECLARE hold_key SMALLINT;
IF lo_sal < 0 THEN
SIGNAL SQLSTATE '75001'
SET MESSAGE_TEXT = 'Salary too low';
END IF;
FOR get_max AS
SELECT id AS in_key
,salary As in_sal
FROM staff
WHERE id >= lo_key
DO
IF in_sal > hold_sal THEN
SET hold_sal = in_sal;
SET hold_key = in_key;
END IF;
END FOR;
RETURN
SELECT id
,salary
,hold_sal
,hold_key ANSWER
FROM staff ============================
WHERE id >= lo_key; ID SALARY MAX_SAL ID_MAX
END! --- -------- -------- ------
70 76502.83 91150.00 140
SELECT * 80 43504.60 91150.00 140
FROM TABLE(staff_list(66,1)) AS ttt 90 38001.75 91150.00 140
WHERE id < 111 100 78352.80 91150.00 140
ORDER BY id! 110 42508.20 91150.00 140
Figure 523, Table function with compound SQL
CREATE FUNCTION julian_out(inval DATE)
RETURNS CHAR(7)
RETURN RTRIM(CHAR(YEAR(inval)))
|| SUBSTR(DIGITS(DAYOFYEAR(inval)),8);
ANSWER
SELECT empno =========================
,CHAR(hiredate,ISO) AS h_date EMPNO H_DATE J_DATE
,JULIAN_OUT(hiredate) AS j_date ------ ---------- -------
FROM employee 000010 1995-01-01 1995001
WHERE empno < '000050' 000020 2003-10-10 2003283
ORDER BY empno; 000030 2005-04-05 2005095
Figure 524, Convert Date into Julian Date
CREATE FUNCTION julian_in(inval CHAR(7))
RETURNS DATE
RETURN DATE('0001-01-01')
+ (INT(SUBSTR(inval,1,4)) - 1) YEARS
+ (INT(SUBSTR(inval,5,3)) - 1) DAYS;
Figure 525, Convert Julian Date into Date
SELECT empno
,hiredate
FROM employee
WHERE YEAR(hiredate) = YEAR(CURRENT DATE) - 1;
Figure 526, Select rows where hire-date = prior year
CREATE FUNCTION year_month(inval DATE)
RETURNS INTEGER
RETURN (YEAR(inval) * 12) + MONTH(inval);
Figure 527, Create year-month function
SELECT empno
,hiredate
FROM employee
WHERE YEAR_MONTH(hiredate) = YEAR_MONTH(CURRENT DATE) - 1;
Figure 528, Select rows where hire-date = prior month
CREATE FUNCTION sunday_week(inval DATE)
RETURNS INTEGER
RETURN DAYS(inval) / 7;
Figure 529, Create week-number function
CREATE FUNCTION monday_week(inval DATE)
RETURNS INTEGER
RETURN (DAYS(inval) - 1) / 7;
Figure 530, Create week-number function
WITH ANSWER
temp1 (num,dt) AS ==================================
(VALUES (1 DATE DAY WK IS SUN_WK MON_WK
,DATE('2004-12-29')) ---------- --- -- -- ------ ------
UNION ALL 2004-12-29 Wed 53 53 104563 104563
SELECT num + 1 2004-12-30 Thu 53 53 104563 104563
,dt + 1 DAY 2004-12-31 Fri 53 53 104563 104563
FROM temp1 2005-01-01 Sat 1 53 104563 104563
WHERE num < 15 2005-01-02 Sun 2 53 104564 104563
), 2005-01-03 Mon 2 1 104564 104564
temp2 (dt,dy) AS 2005-01-04 Tue 2 1 104564 104564
(SELECT dt 2005-01-05 Wed 2 1 104564 104564
,SUBSTR(DAYNAME(dt),1,3) 2005-01-06 Thu 2 1 104564 104564
FROM temp1 2005-01-07 Fri 2 1 104564 104564
) 2005-01-08 Sat 2 1 104564 104564
SELECT CHAR(dt,ISO) AS date 2005-01-09 Sun 3 1 104565 104564
,dy AS day 2005-01-10 Mon 3 2 104565 104565
,WEEK(dt) AS wk 2005-01-11 Tue 3 2 104565 104565
,WEEK_ISO(dt) AS is 2005-01-12 Wed 3 2 104565 104565
,sunday_week(dt) AS sun_wk
,monday_week(dt) AS mon_wk
FROM temp2
ORDER BY 1;
Figure 531, Use week-number functions
CREATE FUNCTION NumList(max_num INTEGER)
RETURNS TABLE(num INTEGER)
LANGUAGE SQL
RETURN
WITH temp1 (num) AS
(VALUES (0)
UNION ALL
SELECT num + 1
FROM temp1
WHERE num < max_num
)
SELECT num
FROM temp1;
Figure 532, Create num-list function
ANSWERS
SELECT * =======
FROM TABLE(NumList(-1)) AS xxx; 0
SELECT *
FROM TABLE(NumList(+0)) AS xxx; 0
SELECT *
FROM TABLE(NumList(+3)) AS xxx; 0
1
2
3
SELECT *
FROM TABLE(NumList(CAST(NULL AS INTEGER))) AS xxx; 0
Figure 533, Using num-list function
SELECT actno ANSWER
,emstdate =================================
,emendate ACTNO EMSTDATE EMENDATE #DAYS
,DAYS(emendate) - ----- ---------- ---------- -----
DAYS(emstdate) AS #days 70 2002-06-15 2002-07-01 16
FROM emp_act act 80 2002-03-01 2002-04-15 45
WHERE empno = '000260'
AND projno = 'AD3113'
AND actno < 100
AND emptime = 0.5
ORDER BY actno;
Figure 534, Select activity start & end date
SELECT actno ANSWER
,#days ==========================
,num ACTNO #DAYS NUM NEW_DATE
,emstdate + num DAYS AS new_date ----- ----- --- ----------
FROM (SELECT actno 70 16 0 2002-06-15
,emstdate 70 16 1 2002-06-16
,emendate 70 16 2 2002-06-17
,DAYS(emendate) - 70 16 3 2002-06-18
DAYS(emstdate) AS #days 70 16 4 2002-06-19
FROM emp_act act 70 16 5 2002-06-20
WHERE empno = '000260' 70 16 6 2002-06-21
AND projno = 'AD3113' 70 16 7 2002-06-22
AND actno < 100 70 16 8 2002-06-23
AND emptime = 0.5 70 16 9 2002-06-24
)AS aaa 70 16 10 2002-06-25
,TABLE(NumList(#days)) AS ttt etc...
ORDER BY actno
,num;
Figure 535, Generate one row per date between start & end dates (1 of 2)
SELECT actno
,#days
,num ACTNO #DAYS NUM NEW_DATE
,emstdate + num DAYS AS new_date ----- ----- --- ----------
FROM (SELECT actno 70 16 0 2002-06-15
,emstdate 70 16 1 2002-06-16
,emendate 70 16 2 2002-06-17
,DAYS(emendate) - 70 16 3 2002-06-18
DAYS(emstdate) AS #days 70 16 4 2002-06-19
FROM emp_act act 70 16 5 2002-06-20
WHERE empno = '000260' 70 16 6 2002-06-21
AND projno = 'AD3113' 70 16 7 2002-06-22
AND actno < 100 70 16 8 2002-06-23
AND emptime = 0.5 70 16 9 2002-06-24
)AS aaa 70 16 10 2002-06-25
LEFT OUTER JOIN etc...
TABLE(NumList(#days)) AS ttt
ON 1 = 1
ORDER BY actno
,num;
Figure 536, Generate one row per date between start & end dates (2 of 2)
CREATE FUNCTION ISCHAR (inval VARCHAR(250))
RETURNS SMALLINT
LANGUAGE SQL
RETURN
CASE
WHEN TRANSLATE(UPPER(inval),' ','ABCDEFGHIJKLMNOPQRSTUVWXYZ') = ' '
THEN 1
ELSE 0
END;
Figure 537, Check if input value is character
CREATE FUNCTION ISNUM (inval VARCHAR(250))
RETURNS SMALLINT
LANGUAGE SQL
RETURN
CASE
WHEN TRANSLATE(inval,' ','01234567890') = ' '
THEN 1
ELSE 0
END;
Figure 538, Check if input value is numeric
WITH temp (indata) AS ANSWER
(VALUES ('ABC'),('123'),('3.4') ==========
,('-44'),('A1 '),(' ')) INDATA C N
SELECT indata AS indata ------ - -
,ISCHAR(indata) AS c ABC 1 0
,ISNUM(indata) AS n 123 0 1
FROM temp; 3.4 0 0
-44 0 0
A1 0 0
1 1
Figure 539, Example of functions in use
CREATE FUNCTION ISNUM2 (inval VARCHAR(255))
RETURNS CHAR(4)
LANGUAGE SQL
RETURN
CASE
WHEN inval = ' '
THEN ' '
WHEN LOCATE(' ',RTRIM(LTRIM(inval))) > 0
THEN ' '
WHEN TRANSLATE(inval,' ','01234567890') = inval
THEN ' '
WHEN TRANSLATE(inval,' ','01234567890') = ' '
THEN 'INT '
WHEN TRANSLATE(inval,' ','+01234567890') = ' '
AND LOCATE('+',LTRIM(inval)) = 1
AND LENGTH(REPLACE(inval,'+','')) = LENGTH(inval) - 1
THEN 'INT+'
WHEN TRANSLATE(inval,' ','-01234567890') = ' '
AND LOCATE('-',LTRIM(inval)) = 1
AND LENGTH(REPLACE(inval,'-','')) = LENGTH(inval) - 1
THEN 'INT-'
WHEN TRANSLATE(inval,' ','.01234567890') = ' '
AND LENGTH(REPLACE(inval,'.','')) = LENGTH(inval) - 1
THEN 'DEC '
WHEN TRANSLATE(inval,' ','+.01234567890') = ' '
AND LOCATE('+',LTRIM(inval)) = 1
AND LENGTH(REPLACE(inval,'+','')) = LENGTH(inval) - 1
AND LENGTH(REPLACE(inval,'.','')) = LENGTH(inval) - 1
THEN 'DEC+'
Figure 540, Check if input value is numeric - part 1 of 2
WHEN TRANSLATE(inval,' ','-.01234567890') = ' '
AND LOCATE('-',LTRIM(inval)) = 1
AND LENGTH(REPLACE(inval,'-','')) = LENGTH(inval) - 1
AND LENGTH(REPLACE(inval,'.','')) = LENGTH(inval) - 1
THEN 'DEC-'
ELSE ' '
END;
Figure 541, Check if input value is numeric - part 2 of 2
WITH temp (indata) AS ANSWER
(VALUES ('ABC'),('123'),('3.4') ==================
,('-44'),('+11'),('-1-') INDATA TYPE NUMBER
,('12+'),('+.1'),('-0.') ------ ---- ------
,(' '),('1 1'),(' . ')) ABC -
SELECT indata AS indata 123 INT 123.00
,ISNUM2(indata) AS type 3.4 DEC 3.40
,CASE -44 INT- -44.00
WHEN ISNUM2(indata) <> '' +11 INT+ 11.00
THEN DEC(indata,5,2) -1- -
ELSE NULL 12+ -
END AS number +.1 DEC+ 0.10
FROM temp; -0. DEC- 0.00
-
1 1 -
. -
Figure 542, Example of function in use
Figure 543, ORDER BY syntax
CREATE VIEW SEQ_DATA(col1,col2)
AS VALUES ('ab','xy')
,('AB','xy')
,('ac','XY')
,('AB','XY')
,('Ab','12');
Figure 544, ORDER BY sample data definition
SELECT col1 ANSWER SEQ_DATA
,col2 ========= +---------+
FROM seq_data COL1 COL2 |COL1|COL2|
ORDER BY col1 ASC ---- ---- |----+----|
,col2; ab xy |ab |xy |
ac XY |AB |xy |
Ab 12 |ac |XY |
AB xy |AB |XY |
AB XY |Ab |12 |
+---------+
Figure 545, Simple ORDER BY
SELECT col1 ANSWER
,col2 =========
FROM seq_data COL1 COL2
ORDER BY TRANSLATE(col1) ASC ---- ----
,TRANSLATE(col2) ASC Ab 12
ab xy
AB XY
AB xy
ac XY
Figure 546, Case insensitive ORDER BY
SELECT col2 ANSWER
FROM seq_data ======
ORDER BY col1 COL2
,col2; ----
xy
XY
12
xy
XY
Figure 547, ORDER BY on not-displayed column
SELECT col1 ANSWER
,col2 =========
FROM seq_data COL1 COL2
ORDER BY SUBSTR(col1,2) DESC ---- ----
,col2 ac XY
,1; AB xy
AB XY
Ab 12
ab xy
Figure 548, ORDER BY second byte of first column
SELECT col1 ANSWER
,HEX(col1) AS hex1 ===================
,col2 COL1 HEX1 COL2 HEX2
,HEX(col2) AS hex2 ---- ---- ---- ----
FROM seq_data AB 4142 XY 5859
ORDER BY HEX(col1) AB 4142 xy 7879
,HEX(col2) Ab 4162 12 3132
ab 6162 xy 7879
ac 6163 XY 5859
Figure 549, ORDER BY in bit-data sequence
SELECT col1 ANSWER SEQ_DATA
FROM (SELECT col1 ====== +---------+
FROM seq_data COL1 |COL1|COL2|
ORDER BY col2 ---- |----+----|
) AS xxx Ab |ab |xy |
ORDER BY ORDER OF xxx; ab |AB |xy |
AB |ac |XY |
ac |AB |XY |
AB |Ab |12 |
+---------+
Figure 550, ORDER BY nested ORDER BY
SELECT * ANSWER
FROM (SELECT * =========
FROM (SELECT * COL1 COL2
FROM seq_data ---- ----
ORDER BY col2 Ab 12
)AS xxx ab xy
ORDER BY ORDER OF xxx AB xy
,SUBSTR(col1,2) AB XY
)AS yyy ac XY
ORDER BY ORDER OF yyy
,col1;
Figure 551, Multiple nested ORDER BY statements
SELECT empno ANSWER
,projno AS prj =================
,actno AS act EMPNO PRJ ACT R#
,ROW_NUMBER() OVER() AS r# ------ --- --- --
FROM FINAL TABLE 400000 ZZZ 999 1
(INSERT INTO emp_act (empno, projno, actno) 400000 VVV 111 2
VALUES ('400000','ZZZ',999)
,('400000','VVV',111))
ORDER BY INPUT SEQUENCE;
Figure 552, ORDER BY insert input sequence
Figure 553, GROUP BY syntax
GROUP BY division, department, team
GROUP BY division, department
GROUP BY division
GROUP BY division, team
GROUP BY department, team
GROUP BY department
GROUP BY team
GROUP BY () <= grand-total
Figure 554, Possible groupings
GROUP BY division, department, team
UNION ALL
GROUP BY division, department
UNION ALL
GROUP BY division
UNION ALL
GROUP BY ()
GROUP BY GROUPING SETS ((division, department, team)
,(division, department)
,(division)
,())
GROUP BY ROLLUP (division, department, team)
Figure 555, Three ways to write the same GROUP BY
CREATE VIEW employee_view AS ANSWER
SELECT SUBSTR(workdept,1,1) AS d1 ==================
,workdept AS dept D1 DEPT SEX SALARY
,sex AS sex -- ---- --- ------
,INTEGER(salary) AS salary A A00 F 52750
FROM employee A A00 M 29250
WHERE workdept < 'D20'; A A00 M 46500
COMMIT; B B01 M 41250
C C01 F 23800
C C01 F 28420
C C01 F 38250
D D11 F 21340
SELECT * D D11 F 22250
FROM employee_view D D11 F 29840
ORDER BY 1,2,3,4; D D11 M 18270
D D11 M 20450
D D11 M 24680
D D11 M 25280
D D11 M 27740
D D11 M 32250
Figure 556, GROUP BY Sample Data
SELECT d1, dept, sex ANSWER
,SUM(salary) AS salary ========================
,SMALLINT(COUNT(*)) AS #rows D1 DEPT SEX SALARY #ROWS
FROM employee_view -- ---- --- ------ -----
WHERE dept <> 'ABC' A A00 F 52750 1
GROUP BY d1, dept, sex A A00 M 75750 2
HAVING dept > 'A0' B B01 M 41250 1
AND (SUM(salary) > 100 C C01 F 90470 3
OR MIN(salary) > 10 D D11 F 73430 3
OR COUNT(*) <> 22) D D11 M 148670 6
ORDER BY d1, dept, sex;
Figure 557, Simple GROUP BY
SELECT sex ANSWER
,SUM(salary) AS salary ================
,SMALLINT(COUNT(*)) AS #rows SEX SALARY #ROWS
FROM employee_view --- ------ -----
WHERE sex IN ('F','M') F 52750 1
GROUP BY dept F 90470 3
,sex F 73430 3
ORDER BY sex; M 75750 2
M 41250 1
M 148670 6
Figure 558, GROUP BY on non-displayed field
SELECT SUM(salary) AS salary ANSWER
,SMALLINT(COUNT(*)) AS #rows ============
FROM employee_view SALARY #ROWS
WHERE d1 <> 'X' ------ -----
GROUP BY SUBSTR(dept,3,1) 128500 3
HAVING COUNT(*) <> 99; 353820 13
Figure 559, GROUP BY on derived field, not shown
SELECT SUBSTR(dept,3,1) AS wpart ANSWER
,SUM(salary) AS salary ==================
,SMALLINT(COUNT(*)) AS #rows WPART SALARY #ROWS
FROM employee_view ----- ------ -----
GROUP BY SUBSTR(dept,3,1) 1 353820 13
ORDER BY wpart DESC; 0 128500 3
Figure 560, GROUP BY on derived field, shown
GROUP BY GROUPING SETS ((A,B,C)) is equivalent to GROUP BY A
,B
,C
GROUP BY GROUPING SETS (A,B,C) is equivalent to GROUP BY A
UNION ALL
GROUP BY B
UNION ALL
GROUP BY C
GROUP BY GROUPING SETS (A,(B,C)) is equivalent to GROUP BY A
UNION ALL
GROUP BY B
,BY C
Figure 561, GROUPING SETS in parenthesis vs. not
GROUP BY GROUPING SETS (A) is equivalent to GROUP BY A
,GROUPING SETS (B) ,B
,GROUPING SETS (C) ,C
GROUP BY GROUPING SETS (A) is equivalent to GROUP BY A
,GROUPING SETS ((B,C)) ,B
,C
GROUP BY GROUPING SETS (A) is equivalent to GROUP BY A
,GROUPING SETS (B,C) ,B
UNION ALL
GROUP BY A
,C
Figure 562, Multiple GROUPING SETS
GROUP BY A is equivalent to GROUP BY A
,GROUPING SETS ((B,C)) ,B
,C
Figure 563, Simple GROUP BY expression and GROUPING SETS combined
GROUP BY A is equivalent to GROUP BY A
,B ,B
,GROUPING SETS ((B,C)) ,C
GROUP BY A is equivalent to GROUP BY A
,B ,B
,GROUPING SETS (B,C) ,C
UNION ALL
GROUP BY A
,B
GROUP BY A is equivalent to GROUP BY A
,B ,B
,C ,C
,GROUPING SETS (B,C) UNION ALL
GROUP BY A
,B
,C
Figure 564, Mixing simple GROUP BY expressions and GROUPING SETS
GROUP BY GROUPING SETS ((A,B,C) is equivalent to GROUP BY A
,(A,B) ,B
,(C)) ,C
UNION ALL
GROUP BY A
,B
UNION ALL
GROUP BY C
GROUP BY GROUPING SETS ((A) is equivalent to GROUP BY A
,(B,C) UNION ALL
,(A) GROUP BY B
,A ,C
,((C))) UNION ALL
GROUP BY A
UNION ALL
GROUP BY A
UNION ALL
GROUP BY C
Figure 565, GROUPING SETS with multiple components
GROUP BY GROUPING SETS ((A,B,C) is equivalent to GROUP BY A
,(A,B) ,B
,(A) ,C
,()) UNION ALL
GROUP BY A
,B
is equivalent to UNION ALL
GROUP BY A
UNION ALL
ROLLUP(A,B,C) grand-totl
Figure 566, GROUPING SET with multiple components, using grand-total
GROUP BY GROUPING SETS ((A,B,C) is equivalent to GROUP BY A
,(A,B) ,B
,(A,C) ,C
,(B,C) UNION ALL
,(A) GROUP BY A
,(B) ,B
,(C) UNION ALL
,()) GROUP BY A
,C
UNION ALL
GROUP BY B
is equivalent to ,C
UNION ALL
GROUP BY A
UNION ALL
CUBE(A,B,C) GROUP BY B
UNION ALL
GROUP BY C
UNION ALL
grand-totl
Figure 567, GROUPING SET with multiple components, using grand-total
SELECT d1 ANSWER
,dept ==============================
,sex D1 DEPT SEX SAL #R DF WF SF
,SUM(salary) AS sal -- ---- --- ------ -- -- -- --
,SMALLINT(COUNT(*)) AS #r A A00 F 52750 1 0 0 0
,GROUPING(d1) AS f1 A A00 M 75750 2 0 0 0
,GROUPING(dept) AS fd B B01 M 41250 1 0 0 0
,GROUPING(sex) AS fs C C01 F 90470 3 0 0 0
FROM employee_view D D11 F 73430 3 0 0 0
GROUP BY GROUPING SETS (d1) D D11 M 148670 6 0 0 0
,GROUPING SETS ((dept,sex))
ORDER BY d1
,dept
,sex;
Figure 568, Multiple GROUPING SETS, making one GROUP BY
SELECT d1 ANSWER
,dept ==============================
,sex D1 DEPT SEX SAL #R F1 FD FS
,SUM(salary) AS sal -- ---- --- ------ -- -- -- --
,SMALLINT(COUNT(*)) AS #r A A00 - 128500 3 0 0 1
,GROUPING(d1) AS f1 A - F 52750 1 0 1 0
,GROUPING(dept) AS fd A - M 75750 2 0 1 0
,GROUPING(sex) AS fs B B01 - 41250 1 0 0 1
FROM employee_view B - M 41250 1 0 1 0
GROUP BY GROUPING SETS (d1) C C01 - 90470 3 0 0 1
,GROUPING SETS (dept,sex) C - F 90470 3 0 1 0
ORDER BY d1 D D11 - 222100 9 0 0 1
,dept D - F 73430 3 0 1 0
,sex; D - M 148670 6 0 1 0
Figure 569, Multiple GROUPING SETS, making two GROUP BY results
SELECT d1 ANSWER
,dept ==============================
,sex D1 DEPT SEX SAL #R F1 FD FS
,SUM(salary) AS sal ------------------------------
,SMALLINT(COUNT(*)) AS #r A A00 F 52750 1 0 0 0
,GROUPING(d1) AS f1 A A00 M 75750 2 0 0 0
,GROUPING(dept) AS fd B B01 M 41250 1 0 0 0
,GROUPING(sex) AS fs C C01 F 90470 3 0 0 0
FROM employee_view D D11 F 73430 3 0 0 0
GROUP BY d1 D D11 M 148670 6 0 0 0
,dept
,GROUPING SETS ((dept,sex))
ORDER BY d1
,dept
,sex;
Figure 570, Repeated field essentially ignored
SELECT d1 ANSWER
,dept ==============================
,sex D1 DEPT SEX SAL #R F1 FD FS
,SUM(salary) AS sal ------------------------------
,SMALLINT(COUNT(*)) AS #r A A00 F 52750 1 0 0 0
,GROUPING(d1) AS f1 A A00 M 75750 2 0 0 0
,GROUPING(dept) AS fd A A00 - 128500 3 0 0 1
,GROUPING(sex) AS fs B B01 M 41250 1 0 0 0
FROM employee_view B B01 - 41250 1 0 0 1
GROUP BY d1 C C01 F 90470 3 0 0 0
,DEPT C C01 - 90470 3 0 0 1
,GROUPING SETS (dept,sex) D D11 F 73430 3 0 0 0
ORDER BY d1 D D11 M 148670 6 0 0 0
,dept D D11 - 222100 9 0 0 1
,sex;
Figure 571, Repeated field impacts query result
GROUP BY d1 is equivalent to GROUP BY d1
,dept ,dept
,GROUPING SETS ((dept,sex)) sex
GROUP BY d1 is equivalent to GROUP BY d1
,dept ,dept
,GROUPING SETS (dept,sex) sex
UNION ALL
GROUP BY d1
,dept
,dept
Figure 572, Repeated field impacts query result
GROUP BY ROLLUP(A,B,C) ===> GROUP BY GROUPING SETS((A,B,C)
,(A,B)
,(A)
,())
GROUP BY ROLLUP(C,B) ===> GROUP BY GROUPING SETS((C,B)
,(C)
,())
GROUP BY ROLLUP(A) ===> GROUP BY GROUPING SETS((A)
,())
Figure 573, ROLLUP vs. GROUPING SETS
GROUP BY ROLLUP(A,(B,C)) ===> GROUP BY GROUPING SETS((A,B,C)
,(A)
,())
Figure 574, ROLLUP vs. GROUPING SETS
GROUP BY ROLLUP(A) ===> GROUP BY GROUPING SETS((A,B,C)
,ROLLUP(B,C) ,(A,B)
,(A)
,(B,C)
,(B)
,())
Figure 575, ROLLUP vs. GROUPING SETS
ROLLUP(A) * ROLLUP(B,C) = GROUPING SETS((A,B,C)
,(A,B)
,(A)
GROUPING SETS((A) * GROUPING SETS((B,C) = ,(B,C)
,()) ,(B) ,(B)
()) ,(())
Figure 576, Multiplying GROUPING SETS
SELECT dept ANSWER
,SUM(salary) AS salary ====================
,SMALLINT(COUNT(*)) AS #rows DEPT SALARY #ROWS FD
,GROUPING(dept) AS fd ---- ------ ----- --
FROM employee_view A00 128500 3 0
GROUP BY dept B01 41250 1 0
ORDER BY dept; C01 90470 3 0
D11 222100 9 0
Figure 577, Simple GROUP BY
SELECT dept ANSWER
,SUM(salary) AS salary ====================
,SMALLINT(COUNT(*)) AS #rows DEPT SALARY #ROWS FD
,GROUPING(dept) AS FD ---- ------ ----- --
FROM employee_view A00 128500 3 0
GROUP BY ROLLUP(dept) B01 41250 1 0
ORDER BY dept; C01 90470 3 0
D11 222100 9 0
- 482320 16 1
Figure 578, GROUP BY with ROLLUP
SELECT dept ANSWER
,SUM(salary) AS salary ====================
,SMALLINT(COUNT(*)) AS #rows DEPT SALARY #ROWS FD
,GROUPING(dept) AS fd ---- ------ ----- --
FROM employee_view A00 128500 3 0
GROUP BY dept B01 41250 1 0
UNION ALL C01 90470 3 0
SELECT CAST(NULL AS CHAR(3)) AS dept D11 222100 9 0
,SUM(salary) AS salary - 482320 16 1
,SMALLINT(COUNT(*)) AS #rows
,CAST(1 AS INTEGER) AS fd
FROM employee_view
ORDER BY dept;
Figure 579, ROLLUP done the old-fashioned way
SELECT dept ANSWER
,SUM(salary) AS salary ====================
,SMALLINT(COUNT(*)) AS #rows DEPT SALARY #ROWS FD
,GROUPING(dept) AS fd ---- ------ ----- --
FROM employee_view A00 128500 3 0
GROUP BY dept A00 128500 3 0
,ROLLUP(dept) B01 41250 1 0
ORDER BY dept; B01 41250 1 0
C01 90470 3 0
C01 90470 3 0
D11 222100 9 0
D11 222100 9 0
Figure 580, Repeating a field in GROUP BY and ROLLUP (error)
GROUP BY dept => GROUP BY dept => GROUP BY dept
,ROLLUP(dept) ,GROUPING SETS((dept) UNION ALL
,()) GROUP BY dept
,()
Figure 581, Repeating a field, explanation
SELECT dept ANSWER
,sex ===========================
,SUM(salary) AS salary DEPT SEX SALARY #ROWS FD FS
,SMALLINT(COUNT(*)) AS #rows ---- --- ------ ----- -- --
,GROUPING(dept) AS fd A00 F 52750 1 0 0
,GROUPING(sex) AS fs A00 M 75750 2 0 0
FROM employee_view A00 - 128500 3 0 1
GROUP BY dept B01 M 41250 1 0 0
,ROLLUP(sex) B01 - 41250 1 0 1
ORDER BY dept C01 F 90470 3 0 0
,sex; C01 - 90470 3 0 1
D11 F 73430 3 0 0
D11 M 148670 6 0 0
D11 - 222100 9 0 1
Figure 582, GROUP BY on 1st field, ROLLUP on 2nd
SELECT dept ANSWER
,sex ===========================
,SUM(salary) AS salary DEPT SEX SALARY #ROWS FD FS
,SMALLINT(COUNT(*)) AS #rows ---- --- ------ ----- -- --
,GROUPING(dept) AS fd A00 F 52750 1 0 0
,GROUPING(sex) AS fs A00 M 75750 2 0 0
FROM employee_view A00 - 128500 3 0 1
GROUP BY ROLLUP(dept B01 M 41250 1 0 0
,sex) B01 - 41250 1 0 1
ORDER BY dept C01 F 90470 3 0 0
,sex; C01 - 90470 3 0 1
D11 F 73430 3 0 0
D11 M 148670 6 0 0
D11 - 222100 9 0 1
- - 482320 16 1 1
Figure 583, ROLLUP on DEPT, then SEX
SELECT sex ANSWER
,dept ===========================
,SUM(salary) AS salary SEX DEPT SALARY #ROWS FD FS
,SMALLINT(COUNT(*)) AS #rows --- ---- ------ ----- -- --
,GROUPING(dept) AS fd F A00 52750 1 0 0
,GROUPING(sex) AS fs F C01 90470 3 0 0
FROM employee_view F D11 73430 3 0 0
GROUP BY ROLLUP(sex F - 216650 7 1 0
,dept) M A00 75750 2 0 0
ORDER BY sex M B01 41250 1 0 0
,dept; M D11 148670 6 0 0
M - 265670 9 1 0
- - 482320 16 1 1
Figure 584, ROLLUP on SEX, then DEPT
SELECT sex ANSWER
,dept ===========================
,SUM(salary) AS salary SEX DEPT SALARY #ROWS FD FS
,SMALLINT(COUNT(*)) AS #rows --- ---- ------ ----- -- --
,GROUPING(dept) AS fd F A00 52750 1 0 0
,GROUPING(sex) AS fs F C01 90470 3 0 0
FROM employee_view F D11 73430 3 0 0
GROUP BY GROUPING SETS ((sex, dept) F - 216650 7 1 0
,(sex) M A00 75750 2 0 0
,()) M B01 41250 1 0 0
ORDER BY sex M D11 148670 6 0 0
,dept; M - 265670 9 1 0
- - 482320 16 1 1
Figure 585, ROLLUP on SEX, then DEPT
SELECT sex ANSWER
,dept ===========================
,SUM(salary) AS salary SEX DEPT SALARY #ROWS FD FS
,SMALLINT(COUNT(*)) AS #rows --- ---- ------ ----- -- --
,GROUPING(dept) AS fd F A00 52750 1 0 0
,GROUPING(sex) AS fs F C01 90470 3 0 0
FROM employee_view F D11 73430 3 0 0
GROUP BY ROLLUP(sex) F - 216650 7 1 0
,ROLLUP(dept) M A00 75750 2 0 0
ORDER BY sex M B01 41250 1 0 0
,dept; M D11 148670 6 0 0
M - 265670 9 1 0
- A00 128500 3 0 1
- B01 41250 1 0 1
- C01 90470 3 0 1
- D11 222100 9 0 1
- - 482320 16 1 1
Figure 586, Two independent ROLLUPS
SELECT dept ANSWER
,sex ===========================
,SUM(salary) AS salary DEPT SEX SALARY #ROWS FD FS
,SMALLINT(COUNT(*)) AS #rows ---- --- ------ ----- -- --
,GROUPING(dept) AS fd A00 F 52750 1 0 0
,GROUPING(sex) AS fs A00 M 75750 2 0 0
FROM employee_view B01 M 41250 1 0 0
GROUP BY ROLLUP((dept,sex)) C01 F 90470 3 0 0
ORDER BY dept D11 F 73430 3 0 0
,sex; D11 M 148670 6 0 0
- - 482320 16 1 1
Figure 587, Combined-field ROLLUP
SELECT SUM(salary) AS salary ANSWER
,SMALLINT(COUNT(*)) AS #rows ============
FROM employee_view SALARY #ROWS
GROUP BY ROLLUP(sex ------ -----
,dept) 482320 16
HAVING GROUPING(dept) = 1
AND GROUPING(sex) = 1
ORDER BY salary;
Figure 588, Use HAVING to get only grand-total row
SELECT SUM(salary) AS salary ANSWER
,SMALLINT(COUNT(*)) AS #rows ============
FROM employee_view SALARY #ROWS
GROUP BY GROUPING SETS(()); ------ -----
482320 16
Figure 589, Use GROUPING SETS to get grand-total row
SELECT SUM(salary) AS salary ANSWER
,SMALLINT(COUNT(*)) AS #rows ============
FROM employee_view SALARY #ROWS
GROUP BY (); ------ -----
482320 16
Figure 590, Use GROUP BY to get grand-total row
SELECT SUM(salary) AS salary ANSWER
,SMALLINT(COUNT(*)) AS #rows ============
FROM employee_view; SALARY #ROWS
------ -----
482320 16
Figure 591, Get grand-total row directly
GROUP BY CUBE(A,B,C) ===> GROUP BY GROUPING SETS((A,B,C)
,(A,B)
,(A,C)
,(B,C)
,(A)
,(B)
,(C)
,())
GROUP BY CUBE(C,B) ===> GROUP BY GROUPING SETS((C,B)
,(C)
,(B)
,())
GROUP BY CUBE(A) ===> GROUP BY GROUPING SETS((A)
,())
Figure 592, CUBE vs. GROUPING SETS
GROUP BY CUBE(A,(B,C)) ===> GROUP BY GROUPING SETS((A,B,C)
,(B,C)
,(A)
,())
Figure 593, CUBE vs. GROUPING SETS
GROUP BY CUBE(A,B) ==> GROUPING SETS((A,B,C),(A,B),(A,B,C),(A,B)
,CUBE(B,C) ,(A,B,C),(A,B),(A,C),(A)
,(B,C),(B),(B,C),(B)
,(B,C),(B),(C),())
Figure 594, CUBE vs. GROUPING SETS
SELECT d1 ANSWER
,dept ==============================
,sex D1 DEPT SEX SAL #R F1 FD FS
,INT(SUM(salary)) AS sal -- ---- --- ------ -- -- -- --
,SMALLINT(COUNT(*)) AS #r A A00 F 52750 1 0 0 0
,GROUPING(d1) AS f1 A A00 M 75750 2 0 0 0
,GROUPING(dept) AS fd A A00 - 128500 3 0 0 1
,GROUPING(sex) AS fs A - F 52750 1 0 1 0
FROM employee_view A - M 75750 2 0 1 0
GROUP BY CUBE(d1, dept, sex) A - - 128500 3 0 1 1
ORDER BY d1 B B01 M 41250 1 0 0 0
,dept B B01 - 41250 1 0 0 1
,sex; B - M 41250 1 0 1 0
B - - 41250 1 0 1 1
C C01 F 90470 3 0 0 0
C C01 - 90470 3 0 0 1
C - F 90470 3 0 1 0
C - - 90470 3 0 1 1
D D11 F 73430 3 0 0 0
D D11 M 148670 6 0 0 0
D D11 - 222100 9 0 0 1
D - F 73430 3 0 1 0
D - M 148670 6 0 1 0
D - - 222100 9 0 1 1
- A00 F 52750 1 1 0 0
- A00 M 75750 2 1 0 0
- A00 - 128500 3 1 0 1
- B01 M 41250 1 1 0 0
- B01 - 41250 1 1 0 1
- C01 F 90470 3 1 0 0
- C01 - 90470 3 1 0 1
- D11 F 73430 3 1 0 0
- D11 M 148670 6 1 0 0
- D11 - 222100 9 1 0 1
- - F 216650 7 1 1 0
- - M 265670 9 1 1 0
- - - 482320 16 1 1 1
Figure 595, CUBE example
SELECT d1 ANSWER
,dept ==============================
,sex D1 DEPT SEX SAL #R F1 FD FS
,INT(SUM(salary)) AS sal -- ---- --- ------ -- -- -- --
,SMALLINT(COUNT(*)) AS #r A A00 F 52750 1 0 0 0
,GROUPING(d1) AS f1 A A00 M 75750 2 0 0 0
,GROUPING(dept) AS fd etc... (same as prior query)
,GROUPING(sex) AS fs
FROM employee_view
GROUP BY GROUPING SETS ((d1, dept, sex)
,(d1,dept)
,(d1,sex)
,(dept,sex)
,(d1)
,(dept)
,(sex)
,())
ORDER BY d1
,dept
,sex;
Figure 596, CUBE expressed using multiple GROUPING SETS
SELECT d1 ANSWER
,dept ==============================
,sex D1 DEPT SEX SAL #R F1 FD FS
,INT(SUM(salary)) AS sal ------------------------------
,SMALLINT(COUNT(*)) AS #r A A00 F 52750 1 0 0 0
,GROUPING(d1) AS f1 A A00 M 75750 2 0 0 0
,GROUPING(dept) AS fd B B01 M 41250 1 0 0 0
,GROUPING(sex) AS fs C C01 F 90470 3 0 0 0
FROM employee_VIEW D D11 F 73430 3 0 0 0
GROUP BY CUBE((d1, dept, sex)) D D11 M 148670 6 0 0 0
ORDER BY d1 - - - 482320 16 1 1 1
,dept
,sex;
Figure 597, CUBE on compound fields
GROUP BY CUBE((A,B,C)) => GROUP BY GROUING SETS((A,B,C) => GROUP BY A
,()) ,B
,C
UNION ALL
GROUP BY()
Figure 598, CUBE on compound field, explanation
SELECT d1 AS d1 ANSWER
,dept AS dpt ==================
,sex AS sx D1 DPT SX SAL R
,INT(SUM(salary)) AS sal -- --- -- ------ -
,SMALLINT(COUNT(*)) AS r A A00 F 52750 1
FROM employee_VIEW A A00 M 75750 2
GROUP BY d1 B B01 M 41250 1
,dept C C01 F 90470 3
,sex D D11 F 73430 3
ORDER BY 1,2,3; D D11 M 148670 6
Figure 599, Basic GROUP BY example
DESIRED SUB-TOTALS EQUIVILENT TO
================== =====================================
D1, DEPT, and SEX. GROUP BY GROUPING SETS ((d1,dept,sex)
D1 and DEPT. ,(d1,dept)
D1 and SEX. ,(d1,sex)
D1. ,(d1)
SEX. ,(sex)
Grand total. EQUIVILENT TO ,())
=======================
GROUP BY ROLLUP(d1,dept)
,ROLLUP(sex)
Figure 600, Sub-totals that we want to get
SELECT *
FROM (SELECT d1 AS d1
,dept AS dpt
,sex AS sx
,INT(SUM(salary)) AS sal
,SMALLINT(COUNT(*)) AS #r
,SMALLINT(GROUPING(d1)) AS g1
,SMALLINT(GROUPING(dept)) AS gd
,SMALLINT(GROUPING(sex)) AS gs
FROM EMPLOYEE_VIEW ANSWER
GROUP BY CUBE(d1,dept,sex) ============================
)AS xxx D1 DPT SX SAL #R G1 GD GS
WHERE (g1,gd,gs) = (0,0,0) -- --- -- ------ -- -- -- --
OR (g1,gd,gs) = (0,0,1) A A00 F 52750 1 0 0 0
OR (g1,gd,gs) = (0,1,0) A A00 M 75750 2 0 0 0
OR (g1,gd,gs) = (0,1,1) A A00 - 128500 3 0 0 1
OR (g1,gd,gs) = (1,1,0) A - F 52750 1 0 1 0
OR (g1,gd,gs) = (1,1,1) A - M 75750 2 0 1 0
ORDER BY 1,2,3; A - - 128500 3 0 1 1
B B01 M 41250 1 0 0 0
B B01 - 41250 1 0 0 1
B - M 41250 1 0 1 0
B - - 41250 1 0 1 1
C C01 F 90470 3 0 0 0
C C01 - 90470 3 0 0 1
C - F 90470 3 0 1 0
C - - 90470 3 0 1 1
D D11 F 73430 3 0 0 0
D D11 M 148670 6 0 0 0
D D11 - 222100 9 0 0 1
D - F 73430 3 0 1 0
D - M 148670 6 0 1 0
D - - 222100 9 0 1 1
- - F 216650 7 1 1 0
- - M 265670 9 1 1 0
- - - 482320 16 1 1 1
Figure 601, Get lots of sub-totals, using CUBE
(G1,GD,GS) = (0,0,0) <== D1, DEPT, SEX
(G1,GD,GS) = (0,0,1) <== D1, DEPT
(G1,GD,GS) = (0,1,0) <== D1, SEX
(G1,GD,GS) = (0,1,1) <== D1,
(G1,GD,GS) = (1,1,0) <== SEX,
(G1,GD,GS) = (1,1,1) <== grand total
Figure 602, Predicates used - explanation
SELECT d1 ANSWER
,dept =====================
,sex D1 DEPT SEX SAL #R
,INT(SUM(salary)) AS sal -- ---- --- ------ --
,SMALLINT(COUNT(*)) AS #r A A00 F 52750 1
FROM employee_view A A00 M 75750 2
GROUP BY ROLLUP(d1,dept) A A00 - 128500 3
,ROLLUP(sex) A - F 52750 1
ORDER BY 1,2,3; A - M 75750 2
A - - 128500 3
B B01 M 41250 1
B B01 - 41250 1
B - M 41250 1
B - - 41250 1
C C01 F 90470 3
C C01 - 90470 3
C - F 90470 3
C - - 90470 3
D D11 F 73430 3
D D11 M 148670 6
D D11 - 222100 9
D - F 73430 3
D - M 148670 6
D - - 222100 9
- - F 216650 7
- - M 265670 9
- - - 482320 16
Figure 603, Get lots of sub-totals, using ROLLUP
SELECT dept, job
,COUNT(*)
FROM staff
GROUP BY dept, job
ORDER BY dept, job;
Figure 604, GROUP BY with ORDER BY
WITH staff2 (dept, avgsal) AS ANSWER
(SELECT dept =================
,AVG(salary) ID NAME DEPT
FROM staff --- -------- ----
GROUP BY dept 160 Molinare 10
HAVING AVG(salary) > 18000 210 Lu 10
) 240 Daniels 10
SELECT a.id 260 Jones 10
,a.name
,a.dept
FROM staff a
,staff2 b
WHERE a.dept = b.dept
ORDER BY a.id;
Figure 605, GROUP BY on one side of join - using common table expression
SELECT a.id ANSWER
,a.name =================
,a.dept ID NAME DEPT
FROM staff a --- -------- ----
,(SELECT dept AS dept 160 Molinare 10
,AVG(salary) AS avgsal 210 Lu 10
FROM staff 240 Daniels 10
GROUP BY dept 260 Jones 10
HAVING AVG(salary) > 18000
)AS b
WHERE a.dept = b.dept
ORDER BY a.id;
Figure 606, GROUP BY on one side of join - using fullselect
SELECT COUNT(*) AS c1 ANSWER
FROM staff ======
WHERE id < 1; 0
SELECT COUNT(*) AS c1 ANSWER
FROM staff ======
WHERE id < 1 no row
GROUP BY id;
Figure 607, COUNT and No Rows
CREATE VIEW staff_v1 AS STAFF_V1 STAFF_V2
SELECT id, name +-----------+ +---------+
FROM staff |ID|NAME | |ID|JOB |
WHERE ID BETWEEN 10 AND 30; |--|--------| |--|------|
|10|Sanders | |20|Sales |
CREATE VIEW staff_v2 AS |20|Pernal | |30|Clerk |
SELECT id, job |30|Marenghi| |30|Mgr |
FROM staff +-----------+ |40|Sales |
WHERE id BETWEEN 20 AND 50 |50|Mgr |
UNION ALL +---------+
SELECT id, 'Clerk' AS job
FROM staff
WHERE id = 30;
Figure 608, Sample Views used in Join Examples
Figure 609, Join Syntax #1
SELECT v1.id JOIN ANSWER
,v1.name =================
,v2.job ID NAME JOB
FROM staff_v1 v1 -- -------- -----
,staff_v2 v2 20 Pernal Sales
WHERE v1.id = v2.id 30 Marenghi Clerk
ORDER BY v1.id 30 Marenghi Mgr
,v2.job;
Figure 610, Sample two-table join
SELECT v1.id JOIN ANSWER
,v2.job =================
,v3.name ID JOB NAME
FROM staff_v1 v1 -- ----- --------
,staff_v2 v2 30 Clerk Marenghi
,staff_v1 v3 30 Mgr Marenghi
WHERE v1.id = v2.id
AND v2.id = v3.id
AND v3.name LIKE 'M%'
ORDER BY v1.name
,v2.job;
Figure 611, Sample three-table join
Figure 612, Join Syntax #2
SELECT v1.id JOIN ANSWER
,v1.name =================
,v2.job ID NAME JOB
FROM staff_v1 v1 -- -------- -----
INNER JOIN 20 Pernal Sales
staff_v2 v2 30 Marenghi Clerk
ON v1.id = v2.id 30 Marenghi Mgr
ORDER BY v1.id
,v2.job;
Figure 613, Sample two-table inner join
SELECT v1.id STAFF_V1 STAFF_V2
,v2.job +-----------+ +---------+
,v3.name |ID|NAME | |ID|JOB |
FROM staff_v1 v1 |--|--------| |--|------|
JOIN |10|Sanders | |20|Sales |
staff_v2 v2 |20|Pernal | |30|Clerk |
ON v1.id = v2.id |30|Marenghi| |30|Mgr |
JOIN +-----------+ |40|Sales |
staff_v1 v3 |50|Mgr |
ON v2.id = v3.id JOIN ANSWER +---------+
WHERE v3.name LIKE 'M%' =================
ORDER BY v1.name ID JOB NAME
,v2.job; -- ----- --------
30 Clerk Marenghi
30 Mgr Marenghi
Figure 614, Sample three-table inner join
FROM clause
JOIN ON clause
WHERE clause
GROUP BY and aggregate
HAVING clause
SELECT list
ORDER BY clause
FETCH FIRST
Figure 615, Query Processing Sequence
SELECT * ANSWER
FROM staff_v1 v1 ====================
LEFT OUTER JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON 1 = 1 10 Sanders - -
AND v1.id = v2.id 20 Pernal 20 Sales
ORDER BY v1.id 30 Marenghi 30 Clerk
,v2.job; 30 Marenghi 30 Mgr
Figure 616, Sample Views used in Join Examples
SELECT * ANSWER
FROM staff_v1 v1 ====================
LEFT OUTER JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON 1 = 1 20 Pernal 20 Sales
WHERE v1.id = v2.id 30 Marenghi 30 Clerk
ORDER BY v1.id 30 Marenghi 30 Mgr
,v2.job;
Figure 617, Sample Views used in Join Examples
STAFF_V1 STAFF_V2 INNER-JOIN ANSWER
+-----------+ +---------+ ====================
|ID|NAME | |ID|JOB | Join on ID ID NAME ID JOB
|--|--------| |--|------| ==========> -- -------- -- -----
|10|Sanders | |20|Sales | 20 Pernal 20 Sales
|20|Pernal | |30|Clerk | 30 Marenghi 30 Clerk
|30|Marenghi| |30|Mgr | 30 Marenghi 30 Mgr
+-----------+ |40|Sales |
|50|Mgr |
+---------+
Figure 618, Example of Inner Join
SELECT * ANSWER
FROM staff_v1 v1 ====================
,staff_v2 v2 ID NAME ID JOB
WHERE v1.id = v2.id -- -------- -- -----
ORDER BY v1.id 20 Pernal 20 Sales
,v2.job; 30 Marenghi 30 Clerk
30 Marenghi 30 Mgr
Figure 619, Inner Join SQL (1 of 2)
SELECT * ANSWER
FROM staff_v1 v1 ====================
INNER JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON v1.id = v2.id 20 Pernal 20 Sales
ORDER BY v1.id 30 Marenghi 30 Clerk
,v2.job; 30 Marenghi 30 Mgr
Figure 620, Inner Join SQL (2 of 2)
SELECT * ANSWER
FROM staff_v1 v1 ====================
INNER JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON v1.id = v2.id 20 Pernal 20 Sales
AND v2.job <> 'Mgr' 30 Marenghi 30 Clerk
ORDER BY v1.id
,v2.job;
Figure 621, Inner join, using ON check
SELECT * ANSWER
FROM staff_v1 v1 ====================
INNER JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON v1.id = v2.id 20 Pernal 20 Sales
WHERE v2.job <> 'Mgr' 30 Marenghi 30 Clerk
ORDER BY v1.id
,v2.job;
Figure 622, Inner join, using WHERE check
STAFF_V1 STAFF_V2 LEFT-OUTER-JOIN ANSWER
+-----------+ +---------+ ======================
|ID|NAME | |ID|JOB | ID NAME ID JOB
|--|--------| |--|------| =========> -- -------- -- -----
|10|Sanders | |20|Sales | 10 Sanders - -
|20|Pernal | |30|Clerk | 20 Pernal 20 Sales
|30|Marenghi| |30|Mgr | 30 Marenghi 30 Clerk
+-----------+ |40|Sales | 30 Marenghi 30 Mgr
|50|Mgr |
+---------+
Figure 623, Example of Left Outer Join
SELECT *
FROM staff_v1 v1
LEFT OUTER JOIN
staff_v2 v2
ON v1.id = v2.id
ORDER BY 1,4;
Figure 624, Left Outer Join SQL (1 of 2)
SELECT v1.* <== This join gets all
,v2.* rows in STAFF_V1
FROM staff_v1 v1 that match rows
,staff_v2 v2 in STAFF_V2.
WHERE v1.id = v2.id
UNION
SELECT v1.* <== This query gets
,CAST(NULL AS SMALLINT) AS id all the rows in
,CAST(NULL AS CHAR(5)) AS job STAFF_V1 with no
FROM staff_v1 v1 matching rows
WHERE v1.id NOT IN in STAFF_V2.
(SELECT id FROM staff_v2)
ORDER BY 1,4;
Figure 625, Left Outer Join SQL (2 of 2)
SELECT * ANSWER
FROM staff_v1 v1 ====================
LEFT OUTER JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON v1.id = v2.id 10 Sanders - -
AND v2.job <> 'Mgr' 20 Pernal 20 Sales
ORDER BY v1.id 30 Marenghi 30 Clerk
,v2.job;
Figure 626, ON check on table being joined to
SELECT * ANSWER
FROM staff_v1 v1 ====================
LEFT OUTER JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON v1.id = v2.id 20 Pernal 20 Sales
WHERE v2.job <> 'Mgr' 30 Marenghi 30 Clerk
ORDER BY v1.id
,v2.job;
Figure 627, WHERE check on table being joined to (1 of 2)
SELECT * ANSWER
FROM staff_v1 v1 ====================
LEFT OUTER JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON v1.id = v2.id 10 Sanders - -
WHERE (v2.job <> 'Mgr' 20 Pernal 20 Sales
OR v2.job IS NULL) 30 Marenghi 30 Clerk
ORDER BY v1.id
,v2.job;
Figure 628, WHERE check on table being joined to (2 of 2)
SELECT * ANSWER
FROM staff_v1 v1 ====================
LEFT OUTER JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON v1.id = v2.id 10 Sanders - -
AND v1.name > 'N' 20 Pernal 20 Sales
ORDER BY v1.id 30 Marenghi - -
,v2.job;
Figure 629, ON check on table being joined from
SELECT * ANSWER
FROM staff_v1 v1 ====================
LEFT OUTER JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON v1.id = v2.id 10 Sanders - -
WHERE v1.name > 'N' 20 Pernal 20 Sales
ORDER BY v1.id
,v2.job;
Figure 630, WHERE check on table being joined from
STAFF_V1 STAFF_V2 RIGHT-OUTER-JOIN ANSWER
+-----------+ +---------+ =======================
|ID|NAME | |ID|JOB | ID NAME ID JOB
|--|--------| |--|------| =========> -- -------- -- -----
|10|Sanders | |20|Sales | 20 Pernal 20 Sales
|20|Pernal | |30|Clerk | 30 Marenghi 30 Clerk
|30|Marenghi| |30|Mgr | 30 Marenghi 30 Mgr
+-----------+ |40|Sales | - - 40 Sales
|50|Mgr | - - 50 Mgr
+---------+
Figure 631, Example of Right Outer Join
SELECT * ANSWER
FROM staff_v1 v1 ====================
RIGHT OUTER JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON v1.id = v2.id 20 Pernal 20 Sales
ORDER BY v2.id 30 Marenghi 30 Clerk
,v2.job; 30 Marenghi 30 Mgr
- - 40 Sales
- - 50 Mgr
Figure 632, Right Outer Join SQL (1 of 2)
SELECT v1.* ANSWER
,v2.* ====================
FROM staff_v1 v1 ID NAME ID JOB
,staff_v2 v2 -- -------- -- -----
WHERE v1.id = v2.id 20 Pernal 20 Sales
UNION 30 Marenghi 30 Clerk
SELECT CAST(NULL AS SMALLINT) AS id 30 Marenghi 30 Mgr
,CAST(NULL AS VARCHAR(9)) AS name - - 40 Sales
,v2.* - - 50 Mgr
FROM staff_v2 v2
WHERE v2.id NOT IN
(SELECT id FROM staff_v1)
ORDER BY 3,4;
Figure 633, Right Outer Join SQL (2 of 2)
STAFF_V1 STAFF_V2 FULL-OUTER-JOIN ANSWER
+-----------+ +---------+ ======================
|ID|NAME | |ID|JOB | ID NAME ID JOB
|--|--------| |--|------| =========> -- -------- -- -----
|10|Sanders | |20|Sales | 10 Sanders - -
|20|Pernal | |30|Clerk | 20 Pernal 20 Sales
|30|Marenghi| |30|Mgr | 30 Marenghi 30 Clerk
+-----------+ |40|Sales | 30 Marenghi 30 Mgr
|50|Mgr | - - 40 Sales
+---------+ - - 50 Mgr
Figure 634, Example of Full Outer Join
SELECT * ANSWER
FROM staff_v1 v1 ====================
FULL OUTER JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON v1.id = v2.id 10 Sanders - -
ORDER BY v1.id 20 Pernal 20 Sales
,v2.id 30 Marenghi 30 Clerk
,v2.job; 30 Marenghi 30 Mgr
- - 40 Sales
- - 50 Mgr
Figure 635, Full Outer Join SQL
SELECT v1.* ANSWER
,v2.* ====================
FROM staff_v1 v1 ID NAME ID JOB
,staff_v2 v2 -- -------- -- -----
WHERE v1.id = v2.id 10 Sanders - -
UNION 20 Pernal 20 Sales
SELECT v1.* 30 Marenghi 30 Clerk
,CAST(NULL AS SMALLINT) AS id 30 Marenghi 30 Mgr
,CAST(NULL AS CHAR(5)) AS job - - 40 Sales
FROM staff_v1 v1 - - 50 Mgr
WHERE v1.id NOT IN
(SELECT id FROM staff_v2)
UNION
SELECT CAST(NULL AS SMALLINT) AS id
,CAST(NULL AS VARCHAR(9)) AS name
,v2.*
FROM staff_v2 v2
WHERE v2.id NOT IN
(SELECT id FROM staff_v1)
ORDER BY 1,3,4;
Figure 636, Full Outer Join SQL
SELECT * ANSWER
FROM staff_v1 v1 ====================
FULL OUTER JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON v1.id = v2.id 10 Sanders - -
ORDER BY v1.id 20 Pernal 20 Sales
,v2.id 30 Marenghi 30 Clerk
,v2.job; 30 Marenghi 30 Mgr
- - 40 Sales
- - 50 Mgr
Figure 637, Full Outer Join, match on keys
SELECT * ANSWER
FROM staff_v1 v1 ====================
FULL OUTER JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON v1.id = v2.id 10 Sanders - -
AND v1.id > 20 20 Pernal - -
ORDER BY v1.id 30 Marenghi 30 Clerk
,v2.id 30 Marenghi 30 Mgr
,v2.job; - - 20 Sales
- - 40 Sales
- - 50 Mgr
Figure 638, Full Outer Join, match on keys > 20
SELECT * ANSWER
FROM staff_v1 v1 ====================
FULL OUTER JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON v1.id = v2.id 10 Sanders - -
AND +1 = -1 20 Pernal - -
ORDER BY v1.id 30 Marenghi - -
,v2.id - - 20 Sales
,v2.job; - - 30 Clerk
- - 30 Mgr
- - 40 Sales
- - 50 Mgr
Figure 639, Full Outer Join, match on keys (no rows match)
SELECT * ANSWER
FROM staff_v1 v1 ====================
FULL OUTER JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON +1 = -1 10 Sanders - -
ORDER BY v1.id 20 Pernal - -
,v2.id 30 Marenghi - -
,v2.job; - - 20 Sales
- - 30 Clerk
- - 30 Mgr
- - 40 Sales
- - 50 Mgr
Figure 640, Full Outer Join, don't match on keys (no rows match)
SELECT * ANSWER
FROM staff_v1 v1 ====================
FULL OUTER JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON +1 <> -1 10 Sanders 20 Sales
ORDER BY v1.id 10 Sanders 30 Clerk
,v2.id 10 Sanders 30 Mgr
,v2.job; 10 Sanders 40 Sales
10 Sanders 50 Mgr
20 Pernal 20 Sales
STAFF_V1 STAFF_V2 20 Pernal 30 Clerk
+-----------+ +---------+ 20 Pernal 30 Mgr
|ID|NAME | |ID|JOB | 20 Pernal 40 Sales
|--|--------| |--|------| 20 Pernal 50 Mgr
|10|Sanders | |20|Sales | 30 Marenghi 20 Sales
|20|Pernal | |30|Clerk | 30 Marenghi 30 Clerk
|30|Marenghi| |30|Mgr | 30 Marenghi 30 Mgr
+-----------+ |40|Sales | 30 Marenghi 40 Sales
|50|Mgr | 30 Marenghi 50 Mgr
+---------+
Figure 641, Full Outer Join, don't match on keys (all rows match)
SELECT * ANSWER
FROM staff_v1 v1 ====================
FULL JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON v1.id = v2.id 20 Pernal 20 Sales
WHERE v1.id = v2.id 30 Marenghi 30 Clerk
ORDER BY 1,3,4; 30 Marenghi 30 Mgr
Figure 642, Full Outer Join, turned into an inner join by WHERE
STAFF_V1 STAFF_V2
+-----------+ +---------+ ANSWER
|ID|NAME | |ID|JOB | OUTER-JOIN CRITERIA ============
|--|--------| |--|------| ==================> ???, DEPENDS
|10|Sanders | |20|Sales | V1.ID = V2.ID
|20|Pernal | |30|Clerk | V1.ID < 30
|30|Marenghi| |30|Mgr |
+-----------+ |40|Sales |
|50|Mgr |
+---------+
Figure 643, Outer join V1.ID < 30, sample data
SELECT * ANSWER
FROM staff_v1 v1 ====================
FULL JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON v1.id = v2.id 10 Sanders - -
WHERE v1.id < 30 20 Pernal 20 Sales
ORDER BY 1,3,4;
Figure 644, Outer join V1.ID < 30, check applied in WHERE (after join)
SELECT * ANSWER
FROM staff_v1 v1 ====================
FULL JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON v1.id = v2.id 10 Sanders - -
AND v1.id < 30 20 Pernal 20 Sales
ORDER BY 1,3,4; 30 Marenghi - -
- - 30 Clerk
- - 30 Mgr
- - 40 Sales
- - 50 Mgr
Figure 645, Outer join V1.ID < 30, check applied in ON (during join)
SELECT * ANSWER
FROM (SELECT * ====================
FROM staff_v1 ID NAME ID JOB
WHERE id < 30) AS v1 -- -------- -- -----
FULL OUTER JOIN 10 Sanders - -
staff_v2 v2 20 Pernal 20 Sales
ON v1.id = v2.id - - 30 Clerk
ORDER BY 1,3,4; - - 30 Mgr
- - 40 Sales
- - 50 Mgr
Figure 646, Outer join V1.ID < 30, check applied in WHERE (before join)
SELECT * ANSWER
FROM staff_v1 v1 ====================
FULL OUTER JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON v1.id = v2.id 10 Sanders - -
WHERE v1.id < 30 20 Pernal 20 Sales
OR v1.id IS NULL - - 40 Sales
ORDER BY 1,3,4; - - 50 Mgr
Figure 647, Outer join V1.ID < 30, (gives wrong answer - see text)
SELECT * ANSWER
FROM staff_v1 v1 ====================
FULL OUTER JOIN ID NAME ID JOB
staff_v2 v2 -- -------- -- -----
ON v1.id = v2.id 10 Sanders - -
WHERE v1.id < 30 20 Pernal 20 Sales
OR v1.id = v2.id 30 Marenghi 30 Clerk
OR v1.id IS NULL 30 Marenghi 30 Mgr
ORDER BY 1,3,4; - - 40 Sales
- - 50 Mgr
Figure 648, Outer join V1.ID < 30, (gives wrong answer - see text)
STAFF_V1 STAFF_V2 CARTESIAN-PRODUCT
+-----------+ +---------+ ====================
|ID|NAME | |ID|JOB | ID NAME ID JOB
|--|--------| |--|------| =========> -- -------- -- -----
|10|Sanders | |20|Sales | 10 Sanders 20 Sales
|20|Pernal | |30|Clerk | 10 Sanders 30 Clerk
|30|Marenghi| |30|Mgr | 10 Sanders 30 Mgr
+-----------+ |40|Sales | 10 Sanders 40 Sales
|50|Mgr | 10 Sanders 50 Mgr
+---------+ 20 Pernal 20 Sales
20 Pernal 30 Clerk
20 Pernal 30 Mgr
20 Pernal 40 Sales
20 Pernal 50 Mgr
30 Marenghi 20 Sales
30 Marenghi 30 Clerk
30 Marenghi 30 Mgr
30 Marenghi 40 Sales
30 Marenghi 50 Mgr
Figure 649, Example of Cartesian Product
SELECT *
FROM staff_v1 v1
,staff_v2 v2
ORDER BY v1.id
,v2.id
,v2.job;
Figure 650, Cartesian Product SQL (1 of 2)
SELECT *
FROM staff_v1 v1
INNER JOIN
staff_v2 v2
ON 'A' <> 'B'
ORDER BY v1.id
,v2.id
,v2.job;
Figure 651, Cartesian Product SQL (2 of 2)
SELECT v2a.id ANSWER
,v2a.job ===========
,v2b.id ID JOB ID
FROM staff_v2 v2a -- ----- --
,staff_v2 v2b 20 Sales 20
WHERE v2a.job = v2b.job 20 Sales 40
AND v2a.id < 40 30 Clerk 30
ORDER BY v2a.id 30 Mgr 30
,v2b.id; 30 Mgr 50
Figure 652, Partial Cartesian Product SQL
SELECT v2.job ANSWER
,COUNT(*) AS #rows ===========
FROM staff_v1 v1 JOB #ROWS
,staff_v2 v2 ----- -----
GROUP BY v2.job Clerk 3
ORDER BY #rows Mgr 6
,v2.job; Sales 6
Figure 653, Partial Cartesian Product SQL, with GROUP BY
SELECT COALESCE(v1.id,v2.id) AS id ANSWER
,COALESCE(v1.name,'?') AS name =================
,v2.job ID NAME JOB
FROM staff_v1 v1 -- -------- -----
FULL OUTER JOIN 10 Sanders -
staff_v2 v2 20 Pernal Sales
ON v1.id = v2.id 30 Marenghi Clerk
ORDER BY v1.id 30 Marenghi Mgr
,v2.job; 40 ? Sales
50 ? Mgr
Figure 654, Use of COALESCE function in outer join
STAFF_V1 STAFF_V2 ANSWER
+-----------+ +---------+ NON-MATCHING ===================
|ID|NAME | |ID|JOB | OUTER-JOIN ID NAME ID JOB
|--|--------| |--|------| ===========> -- ------- -- -----
|10|Sanders | |20|Sales | 10 Sanders - -
|20|Pernal | |30|Clerk | - - 40 Sales
|30|Marenghi| |30|Mgr | - - 50 Mgr
+-----------+ |40|Sales |
|50|Mgr |
+---------+
Figure 655, Example of outer join, only getting the non-matching rows
SELECT v1.* <== Get all the rows
,CAST(NULL AS SMALLINT) AS id in STAFF_V1 that
,CAST(NULL AS CHAR(5)) AS job have no matching
FROM staff_v1 v1 row in STAFF_V2.
WHERE v1.id NOT IN
(SELECT id FROM staff_v2)
UNION
SELECT CAST(NULL AS SMALLINT) AS id <== Get all the rows
,CAST(NULL AS VARCHAR(9)) AS name in STAFF_V2 that
,v2.* have no matching
FROM staff_v2 v2 row in STAFF_V1.
WHERE v2.id NOT IN
(SELECT id FROM staff_v1)
ORDER BY 1,3,4;
Figure 656, Outer Join SQL, getting only non-matching rows
SELECT *
FROM (SELECT v1.* ,'V1' AS flag FROM staff_v1 v1) AS v1
FULL OUTER JOIN
(SELECT v2.* ,'V2' AS flag FROM staff_v2 v2) AS v2
ON v1.id = v2.id
WHERE v1.flag IS NULL ANSWER
OR v2.flag IS NULL =============================
ORDER BY v1.id ID NAME FLAG ID JOB FLAG
,v2.id -- ------- ---- -- ----- ----
,v2.job; 10 Sanders V1 - - -
- - - 40 Sales V2
- - - 50 Mgr V2
Figure 657, Outer Join SQL, getting only non-matching rows
WITH
v1 AS (SELECT v1.* ,'V1' AS flag FROM staff_v1 v1)
,v2 AS (SELECT v2.* ,'V2' AS flag FROM staff_v2 v2)
SELECT *
FROM v1 v1 ANSWER
FULL OUTER JOIN =============================
v2 v2 ID NAME FLAG ID JOB FLAG
ON v1.id = v2.id -- ------- ---- -- ----- ----
WHERE v1.flag IS NULL 10 Sanders V1 - - -
OR v2.flag IS NULL - - - 40 Sales V2
ORDER BY v1.id, v2.id, v2.job; - - - 50 Mgr V2
Figure 658, Outer Join SQL, getting only non-matching rows
SELECT * STAFF_V1 STAFF_V2
FROM staff_v1 v1 +-----------+ +---------+
FULL OUTER JOIN |ID|NAME | |ID|JOB |
staff_v2 v2 |--|--------| |--|------|
ON v1.id = v2.id |10|Sanders | |20|Sales |
WHERE v1.id IS NULL |20|Pernal | |30|Clerk |
OR v2.id IS NULL |30|Marenghi| |30|Mgr |
ORDER BY v1.id +-----------+ |40|Sales |
,v2.id |50|Mgr |
,v2.job; +---------+
Figure 659, Outer Join SQL, getting only non-matching rows
STAFF_V1 STAFF_V2 ANSWER
+-----------+ +---------+ LEFT OUTER JOIN ===================
|ID|NAME | |ID|JOB | ==============> ID NAME ID JOB
|--|--------| |--|------| V1.ID = V2.ID -- ------- -- -----
|10|Sanders | |20|Sales | V1.ID <> 30 10 Sanders - -
|20|Pernal | |30|Clerk | 20 Pernal 20 Sales
|30|Marenghi| |30|Mgr |
+-----------+ |40|Sales |
|50|Mgr |
+---------+
Figure 660, Left outer join example
SELECT v1.id ANSWER
,v1.name =================
,v2.job ID NAME JOB
FROM staff_v1 v1 -- -------- -----
LEFT OUTER JOIN 10 Sanders -
staff_v2 v2 20 Pernal Sales
ON v1.id = v2.id
WHERE v1.id <> 30
ORDER BY v1.id ;
Figure 661, Outer Join done in FROM phrase of SQL
SELECT v1.id ANSWER
,v1.name =================
,(SELECT v2.job ID NAME JB
FROM staff_v2 v2 -- -------- -----
WHERE v1.id = v2.id) AS jb 10 Sanders -
FROM staff_v1 v1 20 Pernal Sales
WHERE v1.id <> 30
ORDER BY v1.id;
Figure 662, Outer Join done in SELECT phrase of SQL
SELECT v1.id ANSWER
,v1.name =================
,(SELECT v2.job ID NAME JB
FROM staff_v2 v2 -- -------- -----
WHERE v1.id = v2.id) AS jb 10 Sanders -
FROM staff_v1 v1 20 Pernal Sales
ORDER BY v1.id;
Figure 663, Outer Join done in SELECT phrase of SQL - gets error
SELECT v1.id ANSWER
,v1.name =================
,(SELECT MAX(v2.job) ID NAME JB
FROM staff_v2 v2 -- -------- -----
WHERE v1.id = v2.id) AS jb 10 Sanders -
FROM staff_v1 v1 20 Pernal Sales
ORDER BY v1.id; 30 Marenghi Mgr
Figure 664, Outer Join done in SELECT phrase of SQL - fixed
SELECT v1.id ANSWER
,v1.name =================
,MAX(v2.job) AS jb ID NAME JB
FROM staff_v1 v1 -- -------- -----
LEFT OUTER JOIN 10 Sanders -
staff_v2 v2 20 Pernal Sales
ON v1.id = v2.id 30 Marenghi Mgr
GROUP BY v1.id
,v1.name
ORDER BY v1.id ;
Figure 665, Same as prior query - using join and GROUP BY
SELECT v2.id ANSWER
,CASE ===========
WHEN v2.job <> 'Mgr' ID J2
THEN v2.job -- --------
ELSE (SELECT v1.name 20 Sales
FROM staff_v1 v1 30 Clerk
WHERE v1.id = v2.id) 30 Marenghi
END AS j2 40 Sales
FROM staff_v2 v2 50 -
ORDER BY v2.id
,j2;
Figure 666, Sample Views used in Join Examples
SELECT v2.id ANSWER
,v2.job ====================
,(SELECT v1.name ID JOB NAME N2
FROM staff_v1 v1 -- ----- -------- --
WHERE v2.id = v1.id) 20 Sales Pernal 6
,(SELECT LENGTH(v1.name) AS n2 30 Clerk Marenghi 8
FROM staff_v1 v1 30 Mgr Marenghi 8
WHERE v2.id = v1.id) 40 Sales - -
FROM staff_v2 v2 50 Mgr - -
ORDER BY v2.id
,v2.job;
Figure 667, Outer Join done in SELECT, 2 columns
SELECT v2.id ANSWER
,v2.job ====================
,v1.name ID JOB NAME N2
,LENGTH(v1.name) AS n2 -- ----- -------- --
FROM staff_v2 v2 20 Sales Pernal 6
LEFT OUTER JOIN 30 Clerk Marenghi 8
staff_v1 v1 30 Mgr Marenghi 8
ON v2.id = v1.id 40 Sales - -
ORDER BY v2.id 50 Mgr - -
,v2.job;
Figure 668, Outer Join done in FROM, 2 columns
SELECT v1.id ANSWER
,v1.name ==================
,(SELECT SUM(x1.id) ID NAME SUM_ID
FROM staff_v1 x1 -- -------- ------
WHERE x1.id <= v1.id 10 Sanders 10
)AS sum_id 20 Pernal 30
FROM staff_v1 v1 30 Marenghi 60
ORDER BY v1.id
,v2.job;
Figure 669, Running total, using JOIN in SELECT
SELECT v1.id ANSWER
,v1.name ==================
,SUM(id) OVER(ORDER BY id) AS sum_id ID NAME SUM_ID
FROM staff_v1 v1 -- -------- ------
ORDER BY v1.id; 10 Sanders 10
20 Pernal 30
30 Marenghi 60
Figure 670, Running total, using OLAP function
STAFF_V1 STAFF_V2 ANSWER
+-----------+ +---------+ =================
|ID|NAME | |ID|JOB | OUTER-JOIN CRITERIA ID NAME JOB
|--|--------| |--|------| ==================> -- -------- -----
|10|Sanders | |20|Sales | V1.ID = V2.ID 10 Sanders -
|20|Pernal | |30|Clerk | V2.JOB LIKE 'S%' 20 Pernal Sales
|30|Marenghi| |30|Mgr | 30 Marenghi -
+-----------+ |40|Sales |
|50|Mgr |
+---------+
Figure 671, Outer join, with WHERE filter
SELECT v1.id ANSWER (WRONG)
,v1.name =================
,v2.job ID NAME JOB
FROM staff_v1 v1 -- -------- -----
LEFT OUTER JOIN 20 Pernal Sales
staff_v2 v2
ON v1.id = v2.id
WHERE v2.job LIKE 'S%'
ORDER BY v1.id
,v2.job;
Figure 672, Outer Join, WHERE done after - wrong
SELECT v1.id ANSWER
,v1.name =================
,v2.job ID NAME JOB
FROM staff_v1 v1 -- -------- -----
LEFT OUTER JOIN 10 Sanders -
(SELECT * 20 Pernal Sales
FROM staff_v2 30 Marenghi -
WHERE job LIKE 'S%'
)AS v2
ON v1.id = v2.id
ORDER BY v1.id
,v2.job;
Figure 673, Outer Join, WHERE done before - correct
SELECT v1.id ANSWER
,v1.name =================
,(SELECT v2.job ID NAME JOB
FROM staff_v2 v2 -- -------- -----
WHERE v1.id = v2.id 10 Sanders -
AND v2.job LIKE 'S%') 20 Pernal Sales
FROM staff_v1 v1 30 Marenghi -
ORDER BY v1.id
,job;
Figure 674, Outer Join, WHERE done independently - correct
SELECT eee.empno ANSWER
,aaa.projno ==========================
,aaa.actno EMPNO PROJNO ACTNO FORMAT
,ppp.photo_format AS format ------ ------ ----- ------
FROM employee eee 000010 MA2110 10 -
LEFT OUTER JOIN 000070 - - -
emp_act aaa 000130 - - bitmap
ON eee.empno = aaa.empno 000150 MA2112 60 bitmap
AND aaa.emptime = 1 000150 MA2112 180 bitmap
AND aaa.projno LIKE 'M%1%' 000160 MA2113 60 -
LEFT OUTER JOIN
emp_photo ppp
ON eee.empno = ppp.empno
AND ppp.photo_format LIKE 'b%'
WHERE eee.lastname LIKE '%A%'
AND eee.empno < '000170'
AND eee.empno <> '000030'
ORDER BY eee.empno;
Figure 675, Join from Employee to Activity and Photo
SELECT eee.empno ANSWER
,aaa.projno ==========================
,aaa.actno EMPNO PROJNO ACTNO FORMAT
,ppp.photo_format AS format ------ ------ ----- ------
FROM employee eee 000010 MA2110 10 -
LEFT OUTER JOIN 000070 - - -
emp_act aaa 000130 - - -
ON eee.empno = aaa.empno 000150 MA2112 60 bitmap
AND aaa.emptime = 1 000150 MA2112 180 bitmap
AND aaa.projno LIKE 'M%1%' 000160 MA2113 60 -
LEFT OUTER JOIN
emp_photo ppp
ON aaa.empno = ppp.empno
AND ppp.photo_format LIKE 'b%'
WHERE eee.lastname LIKE '%A%'
AND eee.empno < '000170'
AND eee.empno <> '000030'
ORDER BY eee.empno;
Figure 676, Join from Employee to Activity, then from Activity to Photo
SELECT eee.workdept AS dp# ANSWER
,eee.empno =======================
,aaa.projno DP# EMPNO PROJNO STAFF
,ppp.prstaff AS staff --- ------ ------ -----
FROM (SELECT * C01 000030 IF1000 2.00
FROM employee C01 000130 IF1000 2.00
WHERE lastname LIKE '%A%'
AND job <> 'DESIGNER'
AND workdept BETWEEN 'B' AND 'E'
)AS eee
LEFT OUTER JOIN
emp_act aaa
ON aaa.empno = eee.empno
AND aaa.emptime <= 0.5
INNER JOIN
project ppp
ON aaa.projno = ppp.projno
AND ppp.projname LIKE '%Q%'
ORDER BY eee.workdept
,eee.empno
,aaa.projno;
Figure 677, Complex join - wrong
SELECT eee.workdept AS dp# ANSWER
,eee.empno =======================
,xxx.projno DP# EMPNO PROJNO STAFF
,xxx.prstaff AS staff --- ------ ------ -----
FROM (SELECT * C01 000030 IF1000 2.00
FROM employee C01 000130 IF1000 2.00
WHERE lastname LIKE '%A%' D21 000070 - -
AND job <> 'DESIGNER' D21 000240 - -
AND workdept BETWEEN 'B' AND 'E'
)AS eee
LEFT OUTER JOIN
(SELECT aaa.empno
,aaa.emptime
,aaa.projno
,ppp.prstaff
FROM emp_act aaa
INNER JOIN
project ppp
ON aaa.projno = ppp.projno
AND ppp.projname LIKE '%Q%'
)AS xxx
ON xxx.empno = eee.empno
AND xxx.emptime <= 0.5
ORDER BY eee.workdept
,eee.empno
,xxx.projno;
Figure 678, Complex join - right
SELECT eee.workdept AS dp# ANSWER
,eee.empno =======================
,aaa.projno DP# EMPNO PROJNO STAFF
,ppp.prstaff AS staff --- ------ ------ -----
FROM (SELECT * C01 000030 IF1000 2.00
FROM employee C01 000130 IF1000 2.00
WHERE lastname LIKE '%A%' D21 000070 - -
AND job <> 'DESIGNER' D21 000240 - -
AND workdept BETWEEN 'B' AND 'E'
)AS eee
LEFT OUTER JOIN
( emp_act aaa
INNER JOIN
project ppp
ON aaa.projno = ppp.projno
AND ppp.projname LIKE '%Q%'
)
ON aaa.empno = eee.empno
AND aaa.emptime <= 0.5
ORDER BY eee.workdept
,eee.empno
,aaa.projno;
Figure 679, Complex join - right
CREATE TABLE table1 TABLE1 TABLE2
(t1a CHAR(1) NOT NULL +-------+ +-----------+
,t1b CHAR(2) NOT NULL |T1A|T1B| |T2A|T2B|T2C|
,PRIMARY KEY(t1a)); |---|---| |---|---|---|
COMMIT; |A |AA | |A |A |A |
|B |BB | |B |A | - |
CREATE TABLE table2 |C |CC | +-----------+
(t2a CHAR(1) NOT NULL +-------+ "-" = null
,t2b CHAR(1) NOT NULL
,t2c CHAR(1));
INSERT INTO table1 VALUES ('A','AA'),('B','BB'),('C','CC');
INSERT INTO table2 VALUES ('A','A','A'),('B','A',NULL);
Figure 680, Sample tables used in sub-query examples
Figure 681, Sub-query syntax diagram
SELECT * ANSWER
FROM table1 =======
WHERE t1a = T1A T1B
(SELECT t2a --- --
FROM table2 A AA
WHERE t2a = 'A');
SUB-Q TABLE1 TABLE2
RESLT +-------+ +-----------+
+---+ |T1A|T1B| |T2A|T2B|T2C|
|T2A| |---|---| |---|---|---|
|---| |A |AA | |A |A |A |
|A | |B |BB | |B |A | - |
+---+ |C |CC | +-----------+
+-------+ "-" = null
Figure 682, No keyword sub-query, works
SELECT * ANSWER
FROM table1 =======
WHERE t1a =
(SELECT t2a
FROM table2);
SUB-Q TABLE1 TABLE2
RESLT +-------+ +-----------+
+---+ |T1A|T1B| |T2A|T2B|T2C|
|T2A| |---|---| |---|---|---|
|---| |A |AA | |A |A |A |
|A | |B |BB | |B |A | - |
|B | |C |CC | +-----------+
+---+ +-------+ "-" = null
Figure 683, No keyword sub-query, fails
SELECT * ANSWER SUB-Q TABLE1 TABLE2
FROM table1 ======= RESLT +-------+ +-----------+
WHERE t1a > ANY T1A T1B +---+ |T1A|T1B| |T2A|T2B|T2C|
(SELECT t2a --- -- |T2A| |---|---| |---|---|---|
FROM table2); B BB |---| |A |AA | |A |A |A |
C CC |A | |B |BB | |B |A | - |
|B | |C |CC | +-----------+
+---+ +-------+ "-" = null
Figure 684, ANY sub-query
SUB-QUERY CHECK EQUIVALENT COLUMN FUNCTION
================ ============================
> ANY(sub-qurey) > MINIMUM(sub-query results)
< ANY(sub-query) < MAXIMUM(sub-query results)
> ALL(sub-query) > MAXIMUM(sub-query results)
< ALL(sub-query) < MINIMUM(sub-query results)
Figure 685, ANY and ALL vs. column functions
SELECT * ANSWER SUB-Q
FROM table1 ======= RESLT
WHERE t1a = ALL T1A T1B +---+
(SELECT t2b --- -- |T2B|
FROM table2 A AA |---|
WHERE t2b >= 'A'); |A |
|A |
+---+
Figure 686, ALL sub-query, with non-empty sub-query result
SELECT * ANSWER SUB-Q
FROM table1 ======= RESLT
WHERE t1a = ALL T1A T1B +---+
(SELECT t2b --- -- |T2B|
FROM table2 A AA |---|
WHERE t2b >= 'X'); B BB +---+
C CC
Figure 687, ALL sub-query, with empty sub-query result
SELECT * ANSWER
FROM table1 ======
WHERE t1a = ALL 0 rows
(SELECT t2b
FROM table2 SQ-#1 SQ-#2 TABLE1 TABLE2
WHERE t2b >= 'X') RESLT RESLT +-------+ +-----------+
AND 0 <> +---+ +---+ |T1A|T1B| |T2A|T2B|T2C|
(SELECT COUNT(*) |T2B| |(*)| |---|---| |---|---|---|
FROM table2 |---| |---| |A |AA | |A |A |A |
WHERE t2b >= 'X'); +---+ |0 | |B |BB | |B |A | - |
+---+ |C |CC | +-----------+
+-------+ "-" = null
Figure 688, ALL sub-query, with extra check for empty set
SELECT * ANSWER TABLE1 TABLE2
FROM table1 ======= +-------+ +-----------+
WHERE EXISTS T1A T1B |T1A|T1B| |T2A|T2B|T2C|
(SELECT * --- -- |---|---| |---|---|---|
FROM table2); A AA |A |AA | |A |A |A |
B BB |B |BB | |B |A | - |
C CC |C |CC | +-----------+
+-------+ "-" = null
Figure 689, EXISTS sub-query, always returns a match
SELECT * ANSWER
FROM table1 ======
WHERE EXISTS 0 rows
(SELECT *
FROM table2
WHERE t2b >= 'X');
Figure 690, EXISTS sub-query, always returns a non-match
SELECT * ANSWER TABLE1 TABLE2
FROM table1 ======= +-------+ +-----------+
WHERE EXISTS T1A T1B |T1A|T1B| |T2A|T2B|T2C|
(SELECT COUNT(*) --- -- |---|---| |---|---|---|
FROM table2 A AA |A |AA | |A |A |A |
WHERE t2b = 'X'); B BB |B |BB | |B |A | - |
C CC |C |CC | +-----------+
+-------+ "-" = null
Figure 691, EXISTS sub-query, always returns a match
SELECT * ANSWERS TABLE1 TABLE2
FROM table1 ======= +-------+ +-----------+
WHERE NOT EXISTS T1A T1B |T1A|T1B| |T2A|T2B|T2C|
(SELECT * --- --- |---|---| |---|---|---|
FROM table2 A AA |A |AA | |A |A |A |
WHERE t2c >= 'A' |B |BB | |B |A | - |
AND t2c <> t1a); |C |CC | +-----------+
+-------+ "-" = null
SELECT *
FROM table1
WHERE t1a = ALL
(SELECT t2c
FROM table2
WHERE t2c >= 'A');
Figure 692, NOT EXISTS vs. ALL, ignore nulls, find match
SELECT * ANSWERS TABLE1 TABLE2
FROM table1 ======= +-------+ +-----------+
WHERE NOT EXISTS T1A T1B |T1A|T1B| |T2A|T2B|T2C|
(SELECT * --- --- |---|---| |---|---|---|
FROM table2 A AA |A |AA | |A |A |A |
WHERE t2c >= 'X' B BB |B |BB | |B |A | - |
AND t2c <> t1a); C CC |C |CC | +-----------+
+-------+ "-" = null
SELECT *
FROM table1
WHERE t1a = ALL
(SELECT t2c
FROM table2
WHERE t2c >= 'X');
Figure 693, NOT EXISTS vs. ALL, ignore nulls, no match
SELECT * ANSWER TABLE1 TABLE2
FROM table1 ======= +-------+ +-----------+
WHERE NOT EXISTS T1A T1B |T1A|T1B| |T2A|T2B|T2C|
(SELECT * --- --- |---|---| |---|---|---|
FROM table2 A AA |A |AA | |A |A |A |
WHERE t2c <> t1a); |B |BB | |B |A | - |
|C |CC | +-----------+
+-------+ "-" = null
SELECT * ANSWER
FROM table1 =======
WHERE t1a = ALL no rows
(SELECT t2c
FROM table2);
Figure 694, NOT EXISTS vs. ALL, process nulls
SELECT * SELECT * SELECT *
FROM table2 FROM table2 FROM table2
WHERE t2c <> 'A'; WHERE t2c <> 'B'; WHERE t2c <> 'C';
ANSWER ANSWER ANSWER
=========== =========== ===========
T2A T2B T2C T2A T2B T2C T2A T2B T2C
--- --- --- --- --- --- --- --- ---
no rows A A A A A A
Figure 695, List of values in T2C <> T1A value
SELECT * ANSWER TABLE1 TABLE2
FROM table1 ======= +-------+ +-----------+
WHERE NOT EXISTS no rows |T1A|T1B| |T2A|T2B|T2C|
(SELECT * |---|---| |---|---|---|
FROM table2 |A |AA | |A |A |A |
WHERE t2c <> t1a |B |BB | |B |A | - |
OR t2c IS NULL); |C |CC | +-----------+
+-------+ "-" = null
Figure 696, NOT EXISTS - same as ALL
SELECT * ANSWER TABLE1 TABLE2
FROM table1 ======= +-------+ +-----------+
WHERE t1a IN T1A T1B |T1A|T1B| |T2A|T2B|T2C|
(SELECT t2a --- -- |---|---| |---|---|---|
FROM table2); A AA |A |AA | |A |A |A |
B BB |B |BB | |B |A | - |
|C |CC | +-----------+
+-------+ "-" = null
Figure 697, IN sub-query example, two matches
SELECT * ANSWER
FROM table1 ======
WHERE t1a IN 0 rows
(SELECT t2a
FROM table2
WHERE t2a >= 'X');
Figure 698, IN sub-query example, no matches
SELECT * ANSWERS TABLE2
FROM table2 =========== +-----------+
WHERE t2c IN T2A T2B T2C |T2A|T2B|T2C|
(SELECT t2c --- --- --- |---|---|---|
FROM table2); A A A |A |A |A |
|B |A | - |
SELECT * +-----------+
FROM table2 "-" = null
WHERE t2c = ANY
(SELECT t2c
FROM table2);
Figure 699, IN and = ANY sub-query examples, with nulls
SELECT * ANSWER TABLE1 TABLE2
FROM table1 ====== +-------+ +-----------+
WHERE t1a NOT IN 0 rows |T1A|T1B| |T2A|T2B|T2C|
(SELECT t2c |---|---| |---|---|---|
FROM table2); |A |AA | |A |A |A |
|B |BB | |B |A | - |
|C |CC | +-----------+
+-------+ "-" = null
Figure 700, NOT IN sub-query example, no matches
SELECT * ANSWER TABLE1 TABLE2
FROM table1 ======= +-------+ +-----------+
WHERE t1a NOT IN T1A T1B |T1A|T1B| |T2A|T2B|T2C|
(SELECT t2c --- -- |---|---| |---|---|---|
FROM table2 B BB |A |AA | |A |A |A |
WHERE t2c IS NOT NULL); C CC |B |BB | |B |A | - |
|C |CC | +-----------+
+-------+ "-" = null
Figure 701, NOT IN sub-query example, matches
SELECT * ANSWER TABLE1 TABLE2
FROM table1 ======= +-------+ +-----------+
WHERE NOT EXISTS T1A T1B |T1A|T1B| |T2A|T2B|T2C|
(SELECT * --- -- |---|---| |---|---|---|
FROM table2 B BB |A |AA | |A |A |A |
WHERE t1a = t2c); C CC |B |BB | |B |A | - |
|C |CC | +-----------+
+-------+ "-" = null
Figure 702, NOT EXISTS sub-query example, matches
SELECT * ANSWER TABLE1 TABLE2
FROM table1 ======= +-------+ +-----------+
WHERE t1a IN T1A T1B |T1A|T1B| |T2A|T2B|T2C|
(SELECT t2a --- -- |---|---| |---|---|---|
FROM table2); A AA |A |AA | |A |A |A |
B BB |B |BB | |B |A | - |
|C |CC | +-----------+
+-------+ "-" = null
Figure 703, Uncorrelated sub-query
SELECT * ANSWER TABLE1 TABLE2
FROM table1 ======= +-------+ +-----------+
WHERE t1a IN T1A T1B |T1A|T1B| |T2A|T2B|T2C|
(SELECT t2a --- -- |---|---| |---|---|---|
FROM table2 A AA |A |AA | |A |A |A |
WHERE t1a = t2a); B BB |B |BB | |B |A | - |
|C |CC | +-----------+
+-------+ "-" = null
Figure 704, Correlated sub-query
SELECT * ANSWER TABLE2
FROM table2 aa =========== +-----------+
WHERE EXISTS T2A T2B T2C |T2A|T2B|T2C|
(SELECT * --- --- --- |---|---|---|
FROM table2 bb A A A |A |A |A |
WHERE aa.t2a = bb.t2b); |B |A | - |
+-----------+
"-" = null
Figure 705,Correlated sub-query, with correlation names
SELECT * ANSWER TABLE1 TABLE2
FROM table1 ====== +-------+ +-----------+
WHERE (t1a,t1b) IN 0 rows |T1A|T1B| |T2A|T2B|T2C|
(SELECT t2a, t2b |---|---| |---|---|---|
FROM table2); |A |AA | |A |A |A |
|B |BB | |B |A | - |
|C |CC | +-----------+
+-------+ "-" = null
SELECT * ANSWER
FROM table1 ======
WHERE EXISTS 0 rows
(SELECT *
FROM table2
WHERE t1a = t2a
AND t1b = t2b);
Figure 706, Multi-field sub-queries, equal checks
SELECT * ANSWER TABLE1 TABLE2
FROM table1 ======= +-------+ +-----------+
WHERE EXISTS T1A T1B |T1A|T1B| |T2A|T2B|T2C|
(SELECT * --- -- |---|---| |---|---|---|
FROM table2 A AA |A |AA | |A |A |A |
WHERE t1a = t2a B BB |B |BB | |B |A | - |
AND t1b >= t2b); |C |CC | +-----------+
+-------+ "-" = null
Figure 707, Multi-field sub-query, with non-equal check
SELECT empno ANSWER
,lastname =========================
,salary EMPNO LASTNAME SALARY
FROM employee ------ --------- --------
WHERE salary > 000010 HAAS 52750.00
(SELECT MAX(salary) 000110 LUCCHESSI 46500.00
FROM employee
WHERE empno NOT IN
(SELECT empno
FROM emp_act
WHERE projno LIKE 'MA%'))
ORDER BY 1;
Figure 708, Nested Sub-Queries
SELECT COUNT(*) AS #rows ANSWER
,MAX(deptno) AS maxdpt =============
FROM department #ROWS MAXDEPT
WHERE deptname LIKE 'Z%' ----- -------
ORDER BY 1; 0 null
Figure 709, Getting a null value from a not null field
SELECT * TABLE1 TABLE2
FROM table1 t1 +-------+ +-----------+
WHERE 0 = |T1A|T1B| |T2A|T2B|T2C|
(SELECT COUNT(*) |---|---| |---|---|---|
FROM table2 t2 |A |AA | |A |A |A |
WHERE t1.t1a = t2.t2c); |B |BB | |B |A | - |
|C |CC | +-----------+
SELECT * +-------+ "-" = null
FROM table1 t1
WHERE NOT EXISTS
(SELECT * ANSWER
FROM table2 t2 =======
WHERE t1.t1a = t2.t2c); T1A T1B
--- ---
SELECT * B BB
FROM table1 C CC
WHERE t1a NOT IN
(SELECT t2c
FROM table2
WHERE t2c IS NOT NULL);
Figure 710, Sub-queries, true if none match
SELECT t1.* ANSWER
FROM table1 t1 =======
LEFT OUTER JOIN T1A T1B
table2 t2 --- ---
ON t1.t1a = t2.t2c B BB
WHERE t2.t2c IS NULL; C CC
Figure 711, Outer join, true if none match
SELECT * TABLE1 TABLE2
FROM table1 t1 +-------+ +-----------+
WHERE EXISTS |T1A|T1B| |T2A|T2B|T2C|
(SELECT * |---|---| |---|---|---|
FROM table2 t2 |A |AA | |A |A |A |
WHERE t1.t1a = t2.t2c); |B |BB | |B |A | - |
|C |CC | +-----------+
SELECT * +-------+ "-" = null
FROM table1 t1
WHERE 1 <=
(SELECT COUNT(*) ANSWER
FROM table2 t2 =======
WHERE t1.t1a = t2.t2c); T1A T1B
--- ---
SELECT * A AA
FROM table1
WHERE t1a = ANY
(SELECT t2c
FROM table2);
SELECT *
FROM table1
WHERE t1a = SOME
(SELECT t2c
FROM table2);
SELECT *
FROM table1
WHERE t1a IN
(SELECT t2c
FROM table2);
Figure 712, Sub-queries, true if any match
WITH t2 AS TABLE1 TABLE2
(SELECT DISTINCT t2c +-------+ +-----------+
FROM table2 |T1A|T1B| |T2A|T2B|T2C|
) |---|---| |---|---|---|
SELECT t1.* |A |AA | |A |A |A |
FROM table1 t1 |B |BB | |B |A | - |
,t2 |C |CC | +-----------+
WHERE t1.t1a = t2.t2c; +-------+ "-" = null
SELECT t1.*
FROM table1 t1 ANSWER
,(SELECT DISTINCT t2c =======
FROM table2 T1A T1B
)AS t2 --- ---
WHERE t1.t1a = t2.t2c; A AA
SELECT t1.*
FROM table1 t1
INNER JOIN
(SELECT DISTINCT t2c
FROM table2
)AS t2
ON t1.t1a = t2.t2c;
Figure 713, Joins, true if any match
SELECT * TABLE1 TABLE2
FROM table1 t1 +-------+ +-----------+
WHERE 10 = |T1A|T1B| |T2A|T2B|T2C|
(SELECT COUNT(*) |---|---| |---|---|---|
FROM table2 t2 |A |AA | |A |A |A |
WHERE t1.t1a = t2.t2b); |B |BB | |B |A | - |
|C |CC | +-----------+
SELECT * +-------+ "-" = null
FROM table1
WHERE EXISTS
(SELECT t2b ANSWER
FROM table2 ======
WHERE t1a = t2b 0 rows
GROUP BY t2b
HAVING COUNT(*) = 10);
SELECT *
FROM table1
WHERE t1a IN
(SELECT t2b
FROM table2
GROUP BY t2b
HAVING COUNT(*) = 10);
Figure 714, Sub-queries, true if ten match (1 of 2)
SELECT * ANSWER
FROM table1 ======
WHERE (t1a,10) IN 0 rows
(SELECT t2b, COUNT(*)
FROM table2
GROUP BY t2b);
Figure 715, Sub-queries, true if ten match (2 of 2)
WITH t2 AS TABLE1 TABLE2
(SELECT t2b +-------+ +-----------+
FROM table2 |T1A|T1B| |T2A|T2B|T2C|
GROUP BY t2b |---|---| |---|---|---|
HAVING COUNT(*) = 10 |A |AA | |A |A |A |
) |B |BB | |B |A | - |
SELECT t1.* |C |CC | +-----------+
FROM table1 t1 +-------+ "-" = null
,t2
WHERE t1.t1a = t2.t2b;
ANSWER
SELECT t1.* ======
FROM table1 t1 0 rows
,(SELECT t2b
FROM table2
GROUP BY t2b
HAVING COUNT(*) = 10
)AS t2
WHERE t1.t1a = t2.t2b;
SELECT t1.*
FROM table1 t1
INNER JOIN
(SELECT t2b
FROM table2
GROUP BY t2b
HAVING COUNT(*) = 10
)AS t2
ON t1.t1a = t2.t2b;
Figure 716, Joins, true if ten match
SELECT * TABLE1 TABLE2
FROM table1 +-------+ +-----------+
WHERE t1a = ALL |T1A|T1B| |T2A|T2B|T2C|
(SELECT t2b |---|---| |---|---|---|
FROM table2); |A |AA | |A |A |A |
|B |BB | |B |A | - |
SELECT * |C |CC | +-----------+
FROM table1 +-------+ "-" = null
WHERE NOT EXISTS
(SELECT * ANSWER
FROM table2 =======
WHERE t1a <> t2b); T1A T1B
--- ---
A AA
Figure 717, Sub-queries, true if all match, find rows
SELECT * ANSWER
FROM table1 =======
WHERE t1a = ALL T1A T1B
(SELECT t2b --- ---
FROM table2 A AA
WHERE t2b >= 'X'); B BB
C CC
SELECT *
FROM table1
WHERE NOT EXISTS
(SELECT *
FROM table2
WHERE t1a <> t2b
AND t2b >= 'X');
Figure 718, Sub-queries, true if all match, empty set
SELECT * TABLE1 TABLE2
FROM table1 +-------+ +-----------+
WHERE t1a = ALL |T1A|T1B| |T2A|T2B|T2C|
(SELECT t2b |---|---| |---|---|---|
FROM table2 |A |AA | |A |A |A |
WHERE t2b >= 'X') |B |BB | |B |A | - |
AND 0 <> |C |CC | +-----------+
(SELECT COUNT(*) +-------+ "-" = null
FROM table2
WHERE t2b >= 'X'); ANSWER
======
SELECT * 0 rows
FROM table1
WHERE t1a IN
(SELECT MAX(t2b)
FROM table2
WHERE t2b >= 'X'
HAVING COUNT(DISTINCT t2b) = 1);
Figure 719, Sub-queries, true if all match, and at least one value found
R1 R1 R1 R1 R1 R1 R1
UNION UNION INTERSECT INTERSECT EXCEPT EXCEPT MINUS
R2 ALL R2 ALL R2 ALL R2
R1 R2 R2 R2 R2
-- -- ----- ----- --------- ----- ------ ------ -----
A A A A A A E A E
A A B A B A C
A B C A C B C
B B D A B E
B B E A C
C C B
C D B
C B
E B
B
C
C
C
C
D
E
Figure 720, Examples of Union, Except, and Intersect
Figure 721, Union, Except, and Intersect syntax
CREATE VIEW R1 (R1)
AS VALUES ('A'),('A'),('A'),('B'),('B'),('C'),('C'),('C'),('E');
CREATE VIEW R2 (R2)
AS VALUES ('A'),('A'),('B'),('B'),('B'),('C'),('D'); ANSWER
======
SELECT R1 R1 R2
FROM R1 -- --
ORDER BY R1; A A
A A
SELECT R2 A B
FROM R2 B B
ORDER BY R2; B B
C C
C D
C
E
Figure 722, Query sample views
SELECT R1 R1 R2 UNION UNION ALL
FROM R1 -- -- ===== =========
UNION A A A A
SELECT R2 A A B A
FROM R2 A B C A
ORDER BY 1; B B D A
B B E A
C C B
SELECT R1 C D B
FROM R1 C B
UNION ALL E B
SELECT R2 B
FROM R2 C
ORDER BY 1; C
C
C
D
E
Figure 723, Union and Union All SQL
SELECT R1 R1 R2 INTERSECT INTERSECT ALL
FROM R1 -- -- ========= =============
INTERSECT A A A A
SELECT R2 A A B A
FROM R2 A B C B
ORDER BY 1; B B B
B B C
SELECT R1 C C
FROM R1 C D
INTERSECT ALL C
SELECT R2 E
FROM R2
ORDER BY 1;
Figure 724, Intersect and Intersect All SQL
SELECT R1 R1 R1
FROM R1 EXCEPT EXCEPT ALL
EXCEPT R1 R2 R2 R2
SELECT R2 -- -- ===== ==========
FROM R2 A A E A
ORDER BY 1; A A C
A B C
SELECT R1 B B E
FROM R1 B B
EXCEPT ALL C C
SELECT R2 C D
FROM R2 C
ORDER BY 1; E
Figure 725, Except and Except All SQL (R1 on top)
SELECT R2 R2 R2
FROM R2 EXCEPT EXCEPT ALL
EXCEPT R1 R2 R1 R1
SELECT R1 -- -- ===== ==========
FROM R1 A A D B
ORDER BY 1; A A D
A B
SELECT R2 B B
FROM R2 B B
EXCEPT ALL C C
SELECT R1 C D
FROM R1 C
ORDER BY 1; E
Figure 726, Except and Except All SQL (R2 on top)
SELECT R1 (SELECT R1 SELECT R1 R1 R2
FROM R1 FROM R1 FROM R1 -- --
UNION UNION UNION A A
SELECT R2 SELECT R2 (SELECT R2 A A
FROM R2 FROM R2 FROM R2 A B
EXCEPT )EXCEPT EXCEPT B B
SELECT R2 SELECT R2 SELECT R2 B B
FROM R2 FROM R2 FROM R2 C C
ORDER BY 1; ORDER BY 1; )ORDER BY 1; C D
C
E
ANSWER ANSWER ANSWER
====== ====== ======
E E A
B
C
E
Figure 727, Use of parenthesis in Union
CREATE TABLE sales_data_2002
(sales_date DATE NOT NULL
,daily_seq# INTEGER NOT NULL
,cust_id INTEGER NOT NULL
,amount DEC(10,2) NOT NULL
,invoice# INTEGER NOT NULL
,sales_rep CHAR(10) NOT NULL
,CONSTRAINT C CHECK (YEAR(sales_date) = 2002)
,PRIMARY KEY (sales_date, daily_seq#));
CREATE TABLE sales_data_2003
(sales_date DATE NOT NULL
,daily_seq# INTEGER NOT NULL
,cust_id INTEGER NOT NULL
,amount DEC(10,2) NOT NULL
,invoice# INTEGER NOT NULL
,sales_rep CHAR(10) NOT NULL
,CONSTRAINT C CHECK (YEAR(sales_date) = 2003)
,PRIMARY KEY (sales_date, daily_seq#));
CREATE VIEW sales_data AS
SELECT *
FROM sales_data_2002
UNION ALL
SELECT *
FROM sales_data_2003;
Figure 728, Define view to combine yearly tables
INSERT INTO sales_data VALUES ('2002-11-22',1,123,100.10,996,'SUE')
,('2002-11-22',2,123,100.10,997,'JOHN')
,('2003-01-01',1,123,100.10,998,'FRED')
,('2003-01-01',2,123,100.10,999,'FRED');
UPDATE sales_data
SET amount = amount / 2
WHERE sales_rep = 'JOHN';
DELETE
FROM sales_data
WHERE sales_date = '2003-01-01'
AND daily_seq# = 2;
Figure 729, Insert, update, and delete using view
SALES_DATE DAILY_SEQ# CUST_ID AMOUNT INVOICE# SALES_REP
---------- ---------- ------- ------ -------- ---------
01/01/2003 1 123 100.10 998 FRED
11/22/2002 1 123 100.10 996 SUE
11/22/2002 2 123 50.05 997 JOHN
Figure 730, View contents after insert, update, delete
CREATE TABLE staff_summary AS
(SELECT dept
,COUNT(*) AS count_rows
,SUM(id) AS sum_id
FROM staff
GROUP BY dept)
DATA INITIALLY DEFERRED REFRESH IMMEDIATE;
Figure 731, Sample materialized query table DDL
ORIGINAL QUERY OPTIMIZED QUERY
============== =================================
SELECT dept SELECT Q1.dept AS "dept"
,AVG(id) ,Q1.sum_id / Q1.count_rows
FROM staff FROM staff_summary AS Q1
GROUP BY dept
Figure 732, Original and optimized queries
Figure 733, Materialized query table DDL, syntax diagram
MATERIALIZED QUERY TABLE ALLOWABLE ACTIONS ON TABLE
========================== =====================================
REFRESH MAINTAINED BY REFRESH TABLE INSERT/UPDATE/DELETE
========= ============= ============= ====================
DEFERRED SYSTEM yes no
USER no yes
IMMEDIATE SYSTEM yes no
Figure 734, Materialized query table options vs. allowable actions
UPDATE DATABASE CONFIGURATION USING dft_refresh_age ANY;
Figure 735, Changing default refresh age for database
Figure 736, Set refresh age command, syntax
SET CURRENT REFRESH AGE 0;
SET CURRENT REFRESH AGE = ANY;
SET CURRENT REFRESH AGE = 99999999999999;
Figure 737, Set refresh age command, examples
UPDATE DATABASE CONFIGURATION USING dft_refresh_age ANY;
Figure 738, Changing default maintained type for database
Figure 739,Set maintained type command, syntax
SET CURRENT MAINTAINED TYPES = ALL;
SET CURRENT MAINTAINED TABLE TYPES = SYSTEM;
SET CURRENT MAINTAINED TABLE TYPES FOR OPTIMIZATION = USER, SYSTEM;
Figure 740, Set maintained type command, examples
UPDATE DATABASE CONFIGURATION USING DFT_QUERYOPT 5;
Figure 741, Changing default maintained type for database
Figure 742,Set maintained type command, syntax
SET CURRENT QUERY OPTIMIZATION = 9;
figure 743, Set query optimization, example
MQT DEFINITION DATABASE/APPLICATION STATUS DB2
========================== =================================== USE
REFRESH MAINTAINED-BY REFRESH-AGE MAINTAINED-TYPE MQT
========= ============== =========== ===================== ===
IMMEDIATE SYSTEM - - Yes
DEFERRED SYSETM ANY ALL or SYSTEM Yes
DEFERRED USER ANY ALL or USER Yes
DEFERRED FEDERATED-TOOL ANY ALL or FEDERATED-TOOL Yes
Figure 744, When DB2 will consider using a materialized query table
SELECT CURRENT REFRESH AGE AS age_ts
,CURRENT TIMESTAMP AS current_ts
,CURRENT QUERY OPTIMIZATION AS q_opt
FROM sysibm.sysdummy1;
Figure 745, Selecting special registers
CREATE TABLE staff_names AS
(SELECT dept
,COUNT(*) AS count_rows
,SUM(salary) AS sum_salary
,AVG(salary) AS avg_salary
,MAX(salary) AS max_salary
,MIN(salary) AS min_salary
,STDDEV(salary) AS std_salary
,VARIANCE(salary) AS var_salary
,CURRENT TIMESTAMP AS last_change
FROM staff
WHERE TRANSLATE(name) LIKE '%A%'
AND salary > 10000
GROUP BY dept
HAVING COUNT(*) = 1
)DATA INITIALLY DEFERRED REFRESH DEFERRED;
Figure 746, Refresh deferred materialized query table DDL
CREATE TABLE emp_summary AS
(SELECT emp.workdept
,COUNT(*) AS num_rows
,COUNT(emp.salary) AS num_salary
,SUM(emp.salary) AS sum_salary
,COUNT(emp.comm) AS num_comm
,SUM(emp.comm) AS sum_comm
FROM employee emp
GROUP BY emp.workdept
)DATA INITIALLY DEFERRED REFRESH IMMEDIATE;
Figure 747, Refresh immediate materialized query table DDL
SELECT emp.workdept
,DEC(SUM(emp.salary),8,2) AS sum_sal
,DEC(AVG(emp.salary),7,2) AS avg_sal
,SMALLINT(COUNT(emp.comm)) AS #comms
,SMALLINT(COUNT(*)) AS #emps
FROM employee emp
WHERE emp.workdept > 'C'
GROUP BY emp.workdept
HAVING COUNT(*) <> 5
AND SUM(emp.salary) > 50000
ORDER BY sum_sal DESC;
Figure 748, Query that uses materialized query table (1 of 3)
SELECT emp.workdept
,COUNT(*) AS #rows
FROM employee emp
WHERE emp.workdept IN
(SELECT deptno
FROM department
WHERE deptname LIKE '%S%')
GROUP BY emp.workdept
HAVING SUM(salary) > 50000;
Figure 749, Query that uses materialized query table (2 of 3)
SELECT #emps
,DEC(SUM(sum_sal),9,2) AS sal_sal
,SMALLINT(COUNT(*)) AS #depts
FROM (SELECT emp.workdept
,DEC(SUM(emp.salary),8,2) AS sum_sal
,MAX(emp.salary) AS max_sal
,SMALLINT(COUNT(*)) AS #emps
FROM employee emp
GROUP BY emp.workdept
)AS XXX
GROUP BY #emps
HAVING COUNT(*) > 1
ORDER BY #emps
FETCH FIRST 3 ROWS ONLY
OPTIMIZE FOR 3 ROWS;
Figure 750, Query that uses materialized query table (3 of 3)
CREATE TABLE staff_all
(id SMALLINT NOT NULL
,name VARCHAR(9) NOT NULL
,job CHAR(5)
,salary DECIMAL(7,2)
,PRIMARY KEY(id));
Figure 751, Create source table
CREATE TABLE staff_all_dup AS
(SELECT *
FROM staff_all)
DATA INITIALLY DEFERRED REFRESH IMMEDIATE;
Figure 752, Create duplicate data table
CREATE TABLE staff_all_dup_some AS
(SELECT *
FROM staff_all
WHERE id < 30)
DATA INITIALLY DEFERRED REFRESH IMMEDIATE;
Figure 753, Create table - duplicate certain rows only
CREATE TABLE staff_to_fire
(id SMALLINT NOT NULL
,name VARCHAR(9) NOT NULL
,dept SMALLINT
,PRIMARY KEY(id));
Figure 754, Create source table
CREATE TABLE staff_combo AS
(SELECT aaa.id AS id1
,aaa.job AS job
,fff.id as id2
,fff.dept AS dept
FROM staff_all aaa
,staff_to_fire fff
WHERE aaa.id = fff.id)
DATA INITIALLY DEFERRED REFRESH IMMEDIATE;
Figure 755, Materialized query table on join
SELECT emp.workdept
,DEC(SUM(emp.salary),8,2) AS sum_sal
,MAX(emp.salary) AS max_sal
FROM employee emp
GROUP BY emp.workdept;
Figure 756, Query that doesn't use materialized query table (1 of 2)
SELECT emp.workdept
,DEC(SUM(emp.salary),8,2) AS sum_sal
,COUNT(DISTINCT salary) AS #salaries
FROM employee emp
GROUP BY emp.workdept;
Figure 757, Query that doesn't use materialized query table (2 of 2)
REFRESH TABLE emp_summary;
COMMIT;
SET INTEGRITY FOR emp_summary iMMEDIATE CHECKED;
COMMIT;
Figure 758, Materialized query table refresh commands
CREATE TABLE dept_emp_summary AS
(SELECT emp.workdept
,dpt.deptname
,COUNT(*) AS num_rows
,COUNT(emp.salary) AS num_salary
,SUM(emp.salary) AS sum_salary
,COUNT(emp.comm) AS num_comm
,SUM(emp.comm) AS sum_comm
FROM employee emp
,department dpt
WHERE dpt.deptno = emp.workdept
GROUP BY emp.workdept
,dpt.deptname
)DATA INITIALLY DEFERRED REFRESH IMMEDIATE;
Figure 759, Multi-table materialized query table DDL
SELECT d.deptname
,d.deptno
,DEC(AVG(e.salary),7,2) AS avg_sal
,SMALLINT(COUNT(*)) AS #emps
FROM department d
,employee e
WHERE e.workdept = d.deptno
AND d.deptname LIKE '%S%'
GROUP BY d.deptname
,d.deptno
HAVING SUM(e.comm) > 4000
ORDER BY avg_sal DESC;
Figure 760, Query that uses materialized query table
SELECT Q2.$C0 AS "deptname"
,Q2.$C1 AS "deptno"
,Q2.$C2 AS "avg_sal"
,Q2.$C3 AS "#emps"
FROM (SELECT Q1.deptname AS $C0
,Q1.workdept AS $C1
,DEC((Q1.sum_salary / Q1.num_salary),7,2) AS $C2
,SMALLINT(Q1.num_rows) AS $C3
FROM dept_emp_summary AS Q1
WHERE (Q1.deptname LIKE '%S%')
AND (4000 < Q1.sum_comm)
)AS Q2
ORDER BY Q2.$C2 DESC;
Figure 761, DB2 generated query to use materialized query table
CREATE TABLE dpt_emp_act_sumry AS
(SELECT emp.workdept
,dpt.deptname
,emp.empno
,emp.firstnme
,SUM(act.emptime) AS sum_time
,COUNT(act.emptime) AS num_time
,COUNT(*) AS num_rows
FROM department dpt
,employee emp
,emp_act act
WHERE dpt.deptno = emp.workdept
AND emp.empno = act.empno
GROUP BY emp.workdept
,dpt.deptname
,emp.empno
,emp.firstnme
)DATA INITIALLY DEFERRED REFRESH IMMEDIATE;
Figure 762, Three-table materialized query table DDL
SELECT d.deptno
,d.deptname
,DEC(AVG(a.emptime),5,2) AS avg_time
FROM department d
,employee e
,emp_act a
WHERE d.deptno = e.workdept
AND e.empno = a.empno
AND d.deptname LIKE '%S%'
AND e.firstnme LIKE '%S%'
GROUP BY d.deptno
,d.deptname
ORDER BY 3 DESC;
Figure 763, Query that uses materialized query table
SELECT Q4.$C0 AS "deptno"
,Q4.$C1 AS "deptname"
,Q4.$C2 AS "avg_time"
FROM (SELECT Q3.$C3 AS $C0
,Q3.$C2 AS $C1
,DEC((Q3.$C1 / Q3.$C0),5,2) AS $C2
FROM (SELECT SUM(Q2.$C2) AS $C0
,SUM(Q2.$C3) AS $C1
,Q2.$C0 AS $C2
,Q2.$C1 AS $C3
FROM (SELECT Q1.deptname AS $C0
,Q1.workdept AS $C1
,Q1.num_time AS $C2
,Q1.sum_time AS $C3
FROM dpt_emp_act_sumry AS Q1
WHERE (Q1.firstnme LIKE '%S%')
AND (Q1.DEPTNAME LIKE '%S%')
)AS Q2
GROUP BY Q2.$C1
,Q2.$C0
)AS Q3
)AS Q4
ORDER BY Q4.$C2 DESC;
Figure 764, DB2 generated query to use materialized query table
CREATE INDEX dpt_emp_act_sumx1
ON dpt_emp_act_sumry
(workdept
,deptname
,empno
,firstnme);
CREATE INDEX dpt_emp_act_sumx2
ON dpt_emp_act_sumry
(num_rows);
Figure 765, Indexes for DPT_EMP_ACT_SUMRY materialized query table
SELECT d.deptno
,d.deptname
,e.empno
,e.firstnme
,INT(AVG(a.emptime)) AS avg_time
FROM department d
,employee e
,emp_act a
WHERE d.deptno = e.workdept
AND e.empno = a.empno
AND d.deptno LIKE 'D%'
GROUP BY d.deptno
,d.deptname
,e.empno
,e.firstnme
ORDER BY 1,2,3,4;
Figure 766, Sample query that use WORKDEPT index
SELECT d.deptno
,d.deptname
,e.empno
,e.firstnme
,COUNT(*) AS #acts
FROM department d
,employee e
,emp_act a
WHERE d.deptno = e.workdept
AND e.empno = a.empno
GROUP BY d.deptno
,d.deptname
,e.empno
,e.firstnme
HAVING COUNT(*) > 4
ORDER BY 1,2,3,4;
Figure 767, Sample query that uses NUM_ROWS index
CREATE TABLE emp_sum AS
(SELECT workdept
,job
,SUM(salary) AS sum_sal
,COUNT(*) AS #emps
,GROUPING(workdept) AS grp_dpt
,GROUPING(job) AS grp_job
FROM employee
GROUP BY CUBE(workdept
,job))
DATA INITIALLY DEFERRED REFRESH DEFERRED
ORGANIZE BY DIMENSIONS (workdept, job)
IN tsempsum;
Figure 768, Materialized query table organized by dimensions
CREATE TABLE emp_sumry AS
(SELECT workdept AS dept
,COUNT(*) AS #rows
,COUNT(salary) AS #sal
,SUM(salary) AS sum_sal
FROM employee emp
GROUP BY emp.workdept
)DATA INITIALLY DEFERRED REFRESH DEFERRED;
Figure 769, Sample materialized query table
CREATE TABLE emp_sumry_s
(dept
,num_rows
,num_sal
,sum_sal
,GLOBALTRANSID
,GLOBALTRANSTIME
)FOR emp_sumry PROPAGATE IMMEDIATE;
Figure 770, Staging table for the above materialized query table
SET INTEGRITY FOR emp_sumry_s STAGING IMMEDIATE UNCHECKED;
REFRESH TABLE emp_sumry;
<< make changes to the source table (i.e. employee) >>
REFRESH TABLE emp_sumry INCREMENTAL;
Figure 771, Enabling and the using a staging table
Figure 772, Identity Column syntax
CREATE TABLE invoice_data
(invoice# INTEGER NOT NULL
GENERATED ALWAYS AS IDENTITY
(START WITH 1
,INCREMENT BY 1
,NO MAXVALUE
,NO CYCLE
,ORDER)
,sale_date DATE NOT NULL
,customer_id CHAR(20) NOT NULL
,product_id INTEGER NOT NULL
,quantity INTEGER NOT NULL
,price DECIMAL(18,2) NOT NULL
,PRIMARY KEY (invoice#));
Figure 773, Identity column, sample table
CREATE TABLE test_data KEY# FIELD - VALUES ASSIGNED
(key# SMALLINT NOT NULL ============================
GENERATED ALWAYS AS IDENTITY 1 2 3 4 5 6 7 8 9 10 11 etc.
,dat1 SMALLINT NOT NULL
,ts1 TIMESTAMP NOT NULL
,PRIMARY KEY(key#));
Figure 774, Identity column, ascending sequence
CREATE TABLE test_data KEY# FIELD - VALUES ASSIGNED
(key# SMALLINT NOT NULL ============================
GENERATED ALWAYS AS IDENTITY 6 3 0 -3 -6 -9 -12 -15 etc.
(START WITH 6
,INCREMENT BY -3
,NO CYCLE
,NO CACHE
,ORDER)
,dat1 SMALLINT NOT NULL
,ts1 TIMESTAMP NOT NULL
,PRIMARY KEY(key#));
Figure 775, Identity column, descending sequence
CREATE TABLE test_data KEY# VALUES ASSIGNED
(key# SMALLINT NOT NULL ============================
GENERATED ALWAYS AS IDENTITY 123 123 123 123 123 123 etc.
(START WITH 123
,MAXVALUE 124
,INCREMENT BY 0
,NO CYCLE
,NO ORDER)
,dat1 SMALLINT NOT NULL
,ts1 TIMESTAMP NOT NULL);
Figure 776, Identity column, dumb sequence
CREATE TABLE test_data KEY# VALUES ASSIGNED
(key# SMALLINT NOT NULL ============================
GENERATED ALWAYS AS IDENTITY 1 3 5 2 4 6 2 4 6 2 4 6 etc.
(START WITH 1
,INCREMENT BY 2
,MAXVALUE 6
,MINVALUE 2
,CYCLE
,NO CACHE
,ORDER)
,dat1 SMALLINT NOT NULL
,ts1 TIMESTAMP NOT NULL);
Figure 777, Identity column, odd values, then even, then stuck
CREATE TABLE invoice_data
(invoice# INTEGER NOT NULL
GENERATED ALWAYS AS IDENTITY
(START WITH 100
,INCREMENT BY 1
,NO CYCLE
,ORDER)
,sale_date DATE NOT NULL
,customer_id CHAR(20) NOT NULL
,product_id INTEGER NOT NULL
,quantity INTEGER NOT NULL
,price DECIMAL(18,2) NOT NULL
,PRIMARY KEY (invoice#));
Figure 778, Identity column, definition
INSERT INTO invoice_data
VALUES (DEFAULT,'2001-11-22','ABC',123,100,10);
SELECT invoice# ANSWER
FROM FINAL TABLE ========
(INSERT INTO invoice_data INVOICE#
(sale_date,customer_id,product_id,quantity,price) --------
VALUES ('2002-11-22','DEF',123,100,10) 101
,('2003-11-22','GHI',123,100,10)); 102
Figure 779, Invoice table, sample inserts
INVOICE# SALE_DATE CUSTOMER_ID PRODUCT_ID QUANTITY PRICE
-------- ---------- ----------- --- ------ -------- -----
100 2001-11-22 ABC 123 100 10.00
101 2002-11-22 DEF 123 100 10.00
102 2003-11-22 GHI 123 100 10.00
Figure 780, Invoice table, after inserts
ALTER TABLE invoice_data
ALTER COLUMN invoice#
RESTART WITH 1000
SET INCREMENT BY 2;
Figure 781, Invoice table, restart identity column value
INSERT INTO invoice_data
VALUES (DEFAULT,'2004-11-24','XXX',123,100,10)
,(DEFAULT,'2004-11-25','YYY',123,100,10);
Figure 782, Invoice table, more sample inserts
INVOICE# SALE_DATE CUSTOMER_ID PRODUCT_ID QUANTITY PRICE
-------- ---------- ----------- ---------- -------- -----
100 2001-11-22 ABC 123 100 10.00
101 2002-11-22 DEF 123 100 10.00
102 2003-11-22 GHI 123 100 10.00
1000 2004-11-24 XXX 123 100 10.00
1002 2004-11-25 YYY 123 100 10.00
Figure 783, Invoice table, after second inserts
Figure 784, Identity Column alter syntax
CREATE TABLE customers
(cust# INTEGER NOT NULL
GENERATED ALWAYS AS IDENTITY (NO CACHE)
,cname CHAR(10) NOT NULL
,ctype CHAR(03) NOT NULL
,PRIMARY KEY (cust#));
COMMIT;
SELECT cust# ANSWER
FROM FINAL TABLE ======
(INSERT INTO customers CUST#
VALUES (DEFAULT,'FRED','XXX')); -----
ROLLBACK; 1
SELECT cust# ANSWER
FROM FINAL TABLE ======
(INSERT INTO customers CUST#
VALUES (DEFAULT,'FRED','XXX')); -----
COMMIT; 2
Figure 785, Gaps in Values, example
SELECT MIN(cust#) AS minc ANSWER
,MAX(cust#) AS maxc ==============
,COUNT(*) AS rows MINC MAXC ROWS
FROM FINAL TABLE ---- ---- ----
(INSERT INTO customers 3 5 3
VALUES (DEFAULT,'FRED','xxx')
,(DEFAULT,'DAVE','yyy')
,(DEFAULT,'JOHN','zzz'));
Figure 786, Selecting identity column values inserted
CREATE TABLE invoice_table
(invoice# INTEGER NOT NULL
GENERATED ALWAYS AS IDENTITY
,sale_date DATE NOT NULL
,customer_id CHAR(20) NOT NULL
,product_id INTEGER NOT NULL
,quantity INTEGER NOT NULL
,price DECIMAL(18,2) NOT NULL
,PRIMARY KEY (invoice#));
COMMIT;
INSERT INTO invoice_table
VALUES (DEFAULT,'2000-11-22','ABC',123,100,10);
WITH temp (id) AS <<< ANSWER
(VALUES (IDENTITY_VAL_LOCAL())) ======
SELECT * ID
FROM temp; --
1
COMMIT;
WITH temp (id) AS <<< ANSWER
(VALUES (IDENTITY_VAL_LOCAL())) ======
SELECT * ID
FROM temp; --
1
Figure 787, IDENTITY_VAL_LOCAL function examples
INSERT INTO invoice_table
VALUES (DEFAULT,'2000-11-23','ABC',123,100,10);
INSERT INTO invoice_table
VALUES (DEFAULT,'2000-11-24','ABC',123,100,10)
,(DEFAULT,'2000-11-25','ABC',123,100,10); ANSWER
==================
SELECT invoice# AS inv# INV# SALE_DATE ID
,sale_date ---- ---------- --
,IDENTITY_VAL_LOCAL() AS id 1 11/22/2000 2
FROM invoice_table 2 11/23/2000 2
ORDER BY 1; 3 11/24/2000 2
COMMIT; 4 11/25/2000 2
Figure 788, IDENTITY_VAL_LOCAL function examples
SELECT invoice# AS inv# ANSWER
,sale_date ==================
,IDENTITY_VAL_LOCAL() AS id INV# SALE_DATE ID
FROM invoice_table ---- ---------- --
WHERE id = IDENTITY_VAL_LOCAL(); 2 11/23/2000 2
Figure 789, IDENTITY_VAL_LOCAL usage in predicate
CREATE SEQUENCE fred SEQ# VALUES ASSIGNED
AS DECIMAL(31) ====================
START WITH 100 100 102 104 106 etc.
INCREMENT BY 2
NO MINVALUE
NO MAXVALUE
NO CYCLE
CACHE 20
ORDER;
Figure 790, Create sequence
ALTER SEQUENCE fred SEQ# VALUES ASSIGNED
RESTART WITH -55 ====================
INCREMENT BY -5 -55 -60 -65 -70 etc.
MINVALUE -1000
MAXVALUE +1000
NO CACHE
NO ORDER
CYCLE;
Figure 791, Alter sequence attributes
CREATE SEQUENCE biggest_sale_to_date SEQ# VALUES ASSIGNED
AS INTEGER ====================
START WITH 345678 345678, 345678, etc.
INCREMENT BY 0;
Figure 792, Sequence that doesn't change
CREATE SEQUENCE fred; ANSWER
COMMIT; ======
SEQ#
WITH temp1 (n1) AS ----
(VALUES 1 1
UNION ALL 2
SELECT n1 + 1 3
FROM temp1 4
WHERE n1 < 5 5
)
SELECT NEXTVAL FOR fred AS seq#
FROM temp1;
Figure 793, Selecting the NEXTVAL
CREATE SEQUENCE fred; ANSWERS
COMMIT; =======
WITH temp1 (prv) AS ===> PRV
(VALUES (PREVVAL FOR fred)) ---
SELECT *
FROM temp1;
WITH temp1 (nxt) AS ===> NXT
(VALUES (NEXTVAL FOR fred)) ---
SELECT * 1
FROM temp1;
WITH temp1 (prv) AS ===> PRV
(VALUES (PREVVAL FOR fred)) ---
SELECT * 1
FROM temp1;
WITH temp1 (n1) AS ===> NXT PRV
(VALUES 1 --- ---
UNION ALL 2 1
SELECT n1 + 1 3 1
FROM temp1 4 1
WHERE n1 < 5 5 1
) 6 1
SELECT NEXTVAL FOR fred AS nxt
,PREVVAL FOR fred AS prv
FROM temp1;
Figure 794, Use of NEXTVAL and PREVVAL expressions
CREATE SEQUENCE fred; ANSWERS
COMMIT; =======
WITH temp1 AS ===> ID NXT
(SELECT id -- ---
,NEXTVAL FOR fred AS nxt 50 5
FROM staff
WHERE id < 100
)
SELECT *
FROM temp1
WHERE id = 50 + (nxt * 0);
WITH temp1 (nxt, prv) AS ===> NXT PRV
(VALUES (NEXTVAL FOR fred --- ---
,PREVVAL FOR fred)) 10 9
SELECT *
FROM temp1;
Figure 795, NEXTVAL values used but not retrieved
CREATE SEQUENCE cust#
START WITH 1
INCREMENT BY 1
NO MAXVALUE
NO CYCLE
ORDER;
CREATE TABLE us_customer
(cust# INTEGER NOT NULL
,cname CHAR(10) NOT NULL
,frst_sale DATE NOT NULL
,#sales INTEGER NOT NULL
,PRIMARY KEY (cust#));
CREATE TRIGGER us_cust_ins
NO CASCADE BEFORE INSERT ON us_customer
REFERENCING NEW AS nnn
FOR EACH ROW MODE DB2SQL
SET nnn.cust# = NEXTVAL FOR cust#;
CREATE TABLE intl_customer
(cust# INTEGER NOT NULL
,cname CHAR(10) NOT NULL
,frst_sale DATE NOT NULL
,#sales INTEGER NOT NULL
,PRIMARY KEY (cust#));
CREATE TRIGGER intl_cust_ins
NO CASCADE BEFORE INSERT ON intl_customer
REFERENCING NEW AS nnn
FOR EACH ROW MODE DB2SQL
SET nnn.cust# = NEXTVAL FOR cust#;
Figure 796, Create tables that use a common sequence
SELECT cust# ANSWERS
,cname ===========
FROM FINAL TABLE CUST# CNAME
(INSERT INTO us_customer (cname, frst_sale, #sales) ----- -----
VALUES ('FRED','2002-10-22',1) 1 FRED
,('JOHN','2002-10-23',1)); 2 JOHN
SELECT cust#
,cname
FROM FINAL TABLE CUST# CNAME
(INSERT INTO intl_customer (cname, frst_sale, #sales) ----- -----
VALUES ('SUE','2002-11-12',2) 3 SUE
,('DEB','2002-11-13',2)); 4 DEB
Figure 797, Insert into tables with common sequence
WITH temp (prev) AS ANSWER
(VALUES (PREVVAL FOR cust#)) ======
SELECT * PREV
FROM temp; ----
4
Figure 798, Get previous value - select
VALUES PREVVAL FOR CUST# INTO :host-var
Figure 799, Get previous value - into host-variable
CREATE SEQUENCE delete_rows
START WITH 1
INCREMENT BY 1
NO MAXVALUE
NO CYCLE
ORDER;
CREATE SEQUENCE delete_stmts
START WITH 1
INCREMENT BY 1
NO MAXVALUE
NO CYCLE
ORDER;
CREATE TABLE customer
(cust# INTEGER NOT NULL
,cname CHAR(10) NOT NULL
,frst_sale DATE NOT NULL
,#sales INTEGER NOT NULL
,PRIMARY KEY (cust#));
CREATE TRIGGER cust_del_rows
AFTER DELETE ON customer
FOR EACH ROW MODE DB2SQL
WITH temp1 (n1) AS (VALUES(1))
SELECT NEXTVAL FOR delete_rows
FROM temp1;
CREATE TRIGGER cust_del_stmts
AFTER DELETE ON customer
FOR EACH STATEMENT MODE DB2SQL
WITH temp1 (n1) AS (VALUES(1))
SELECT NEXTVAL FOR delete_stmts
FROM temp1;
Figure 800, Count deletes done to table
CREATE TABLE sales_invoice
(invoice# INTEGER NOT NULL
,sale_date DATE NOT NULL
,customer_id CHAR(20) NOT NULL
,product_id INTEGER NOT NULL
,quantity INTEGER NOT NULL
,price DECIMAL(18,2) NOT NULL
,PRIMARY KEY (invoice#));
Figure 801, Sample table, roll your own sequence#
CREATE TRIGGER sales_insert
NO CASCADE BEFORE
INSERT ON sales_invoice
REFERENCING NEW AS nnn
FOR EACH ROW
MODE DB2SQL
SET nnn.invoice# =
(SELECT COALESCE(MAX(invoice#),0) + 1
FROM sales_invoice);
Figure 802, Sample trigger, roll your own sequence#
INSERT INTO sales_invoice VALUES (0,'2001-06-22','ABC',123,10,1);
INSERT INTO sales_invoice VALUES (0,'2001-06-23','DEF',453,10,1);
COMMIT;
INSERT INTO sales_invoice VALUES (0,'2001-06-24','XXX',888,10,1);
ROLLBACK;
INSERT INTO sales_invoice VALUES (0,'2001-06-25','YYY',999,10,1);
COMMIT;
ANSWER
==============================================================
INVOICE# SALE_DATE CUSTOMER_ID PRODUCT_ID QUANTITY PRICE
-------- ---------- ----------- ---------- -------- -----
1 06/22/2001 ABC 123 10 1.00
2 06/23/2001 DEF 453 10 1.00
3 06/25/2001 YYY 999 10 1.00
Figure 803, Sample inserts, roll your own sequence#
CREATE TABLE control_table
(table_name CHAR(18) NOT NULL
,table_nmbr INTEGER NOT NULL
,PRIMARY KEY (table_name));
Figure 804, Control Table, DDL
INSERT INTO control_table VALUES ('invoice_table',0);
INSERT INTO control_table VALUES ('2nd_data_tble',0);
INSERT INTO control_table VALUES ('3rd_data_tble',0);
Figure 805, Control Table, sample inserts
CREATE TABLE invoice_table
(unqval CHAR(13) FOR BIT DATA NOT NULL
,invoice# INTEGER
,sale_date DATE NOT NULL
,customer_id CHAR(20) NOT NULL
,product_id INTEGER NOT NULL
,quantity INTEGER NOT NULL
,price DECIMAL(18,2) NOT NULL
,PRIMARY KEY(unqval));
Figure 806, Sample Data Table, DDL
CREATE TRIGGER invoice1
NO CASCADE BEFORE INSERT ON invoice_table
REFERENCING NEW AS nnn
FOR EACH ROW MODE DB2SQL
SET nnn.unqval = GENERATE_UNIQUE()
,nnn.invoice# = NULL;
Figure 807, Before trigger
CREATE TRIGGER invoice2
AFTER INSERT ON invoice_table
REFERENCING NEW AS nnn
FOR EACH ROW MODE DB2SQL
BEGIN ATOMIC
UPDATE control_table
SET table_nmbr = table_nmbr + 1
WHERE table_name = 'invoice_table';
UPDATE invoice_table
SET invoice# =
(SELECT table_nmbr
FROM control_table
WHERE table_name = 'invoice_table')
WHERE unqval = nnn.unqval
AND invoice# IS NULL;
END
Figure 808, After trigger
CREATE TRIGGER invoice3
NO CASCADE BEFORE UPDATE OF invoice# ON invoice_table
REFERENCING OLD AS ooo
NEW AS nnn
FOR EACH ROW MODE DB2SQL
WHEN (ooo.invoice# <> nnn.invoice#)
SIGNAL SQLSTATE '71001' ('no updates allowed - you twit');
Figure 809, Update trigger
SELECT id
,salary
FROM (SELECT s.*
,ROW_NUMBER() OVER(ORDER BY salary DESC) AS sorder
FROM staff s
WHERE id < 200 ANSWER
)AS xxx =============
WHERE sorder BETWEEN 2 AND 3 ID SALARY
ORDER BY id; --- --------
50 20659.80
140 21150.00
Figure 810, Nested Table Expression
WITH xxx (id, salary, sorder) AS
(SELECT ID
,salary
,ROW_NUMBER() OVER(ORDER BY salary DESC) AS sorder
FROM staff
WHERE id < 200
) ANSWER
SELECT id =============
,salary ID SALARY
FROM xxx --- --------
WHERE sorder BETWEEN 2 AND 3 50 20659.80
ORDER BY id; 140 21150.00
Figure 811, Common Table Expression
WITH ANSWER
rows_wanted AS ================================
(SELECT * ID NAME SALARY SUM_SAL PCT
FROM staff -- ------- -------- -------- ---
WHERE id < 100 70 Rothman 16502.83 34504.58 47
AND UCASE(name) LIKE '%T%' 90 Koonitz 18001.75 34504.58 52
),
sum_salary AS
(SELECT SUM(salary) AS sum_sal
FROM rows_wanted)
SELECT id
,name
,salary
,sum_sal
,INT((salary * 100) / sum_sal) AS pct
FROM rows_wanted
,sum_salary
ORDER BY id;
Figure 812, Common Table Expression
DECLARE GLOBAL TEMPORARY TABLE session.fred
(dept SMALLINT NOT NULL
,avg_salary DEC(7,2) NOT NULL
,num_emps SMALLINT NOT NULL)
ON COMMIT PRESERVE ROWS;
COMMIT;
INSERT INTO session.fred
SELECT dept
,AVG(salary)
,COUNT(*) ANSWER#1
FROM staff ========
WHERE id > 200 CNT
GROUP BY dept; ---
COMMIT; 4
SELECT COUNT(*) AS cnt
FROM session.fred; ANSWER#2
==========================
DELETE FROM session.fred DEPT AVG_SALARY NUM_EMPS
WHERE dept > 80; ---- ---------- --------
10 20168.08 3
SELECT * 51 15161.43 3
FROM session.fred; 66 17215.24 5
Figure 813, Declared Global Temporary Table
WITH staff_dept AS ANSWER
(SELECT dept AS dept# ==========================
,MAX(salary) AS max_sal ID DEPT SALARY MAX_SAL
FROM staff --- ---- -------- --------
WHERE dept < 50 10 20 18357.50 18357.50
GROUP BY dept 190 20 14252.75 18357.50
) 200 42 11508.60 18352.80
SELECT id 220 51 17654.50 -
,dept
,salary
,max_sal
FROM staff
LEFT OUTER JOIN
staff_dept
ON dept = dept#
WHERE name LIKE 'S%'
ORDER BY id;
Figure 814, Identical query (1 of 3) - using Common Table Expression
SELECT id ANSWER
,dept ==========================
,salary ID DEPT SALARY MAX_SAL
,max_sal --- ---- -------- --------
FROM staff 10 20 18357.50 18357.50
LEFT OUTER JOIN 190 20 14252.75 18357.50
(SELECT dept AS dept# 200 42 11508.60 18352.80
,MAX(salary) AS max_sal 220 51 17654.50 -
FROM staff
WHERE dept < 50
GROUP BY dept
)AS STAFF_dept
ON dept = dept#
WHERE name LIKE 'S%'
ORDER BY id;
Figure 815, Identical query (2 of 3) - using fullselect in FROM
SELECT id ANSWER
,dept ==========================
,salary ID DEPT SALARY MAX_SAL
,(SELECT MAX(salary) --- ---- -------- --------
FROM staff s2 10 20 18357.50 18357.50
WHERE s1.dept = s2.dept 190 20 14252.75 18357.50
AND s2.dept < 50 200 42 11508.60 18352.80
GROUP BY dept) 220 51 17654.50 -
AS max_sal
FROM staff s1
WHERE name LIKE 'S%'
ORDER BY id;
Figure 816, Identical query (3 of 3) - using fullselect in SELECT
Figure 817, Common Table Expression Syntax
WITH temp1 AS ANSWER
(SELECT MAX(name) AS max_name ==================
,MAX(dept) AS max_dept MAX_NAME MAX_DEPT
FROM staff --------- --------
) Yamaguchi 84
SELECT *
FROM temp1;
Figure 818, Common Table Expression, using named fields
WITH temp1 (max_name,max_dept) AS ANSWER
(SELECT MAX(name) ==================
,MAX(dept) MAX_NAME MAX_DEPT
FROM staff --------- --------
) Yamaguchi 84
SELECT *
FROM temp1;
Figure 819, Common Table Expression, using unnamed fields
WITH ANSWER
temp1 AS ==========
(SELECT dept MAX_AVG
,AVG(salary) AS avg_sal ----------
FROM staff 20865.8625
GROUP BY dept),
temp2 AS
(SELECT MAX(avg_sal) AS max_avg
FROM temp1)
SELECT *
FROM temp2;
Figure 820, Query with two common table expressions
SELECT * ANSWER
FROM (SELECT MAX(avg_sal) AS max_avg ==========
FROM (SELECT dept MAX_AVG
,AVG(salary) AS avg_sal ----------
FROM staff 20865.8625
GROUP BY dept
)AS temp1
)AS temp2;
Figure 821, Same as prior example, but using nested table expressions
WITH temp1 AS ANSWER
(SELECT id ==========================
,name ID DEPT SALARY MAX_SAL
,dept --- ---- -------- --------
,salary 10 20 18357.50 18357.50
FROM staff 190 20 14252.75 18357.50
WHERE id < 300 200 42 11508.60 11508.60
AND dept <> 55 220 51 17654.50 17654.50
AND name LIKE 'S%'
AND dept NOT IN
(SELECT deptnumb
FROM org
WHERE division = 'SOUTHERN'
OR location = 'HARTFORD')
)
,temp2 AS
(SELECT dept
,MAX(salary) AS max_sal
FROM temp1
GROUP BY dept
)
SELECT t1.id
,t1.dept
,t1.salary
,t2.max_sal
FROM temp1 t1
,temp2 t2
WHERE t1.dept = t2.dept
ORDER BY t1.id;
Figure 822, Deriving second temporary table from first
INSERT INTO staff
WITH temp1 (max1) AS
(SELECT MAX(id) + 1
FROM staff
)
SELECT max1,'A',1,'B',2,3,4
FROM temp1;
Figure 823, Insert using common table expression
INSERT INTO staff
SELECT MAX(id) + 1
,'A',1,'B',2,3,4
FROM staff;
Figure 824, Equivalent insert (to above) without common table expression
SELECT division
,DEC(AVG(dept_avg),7,2) AS div_dept
,COUNT(*) AS #dpts
,SUM(#emps) AS #emps
FROM (SELECT division
,dept
,AVG(salary) AS dept_avg
,COUNT(*) AS #emps
FROM staff ANSWER
,org ==============================
WHERE dept = deptnumb DIVISION DIV_DEPT #DPTS #EMPS
GROUP BY division --------- -------- ----- -----
,dept Corporate 20865.86 1 4
)AS xxx Eastern 15670.32 3 13
GROUP BY division; Midwest 15905.21 2 9
Western 16875.99 2 9
Figure 825, Nested column function usage
SELECT id ANSWER
FROM (SELECT * ======
FROM (SELECT id, years, salary ID
FROM (SELECT * ---
FROM (SELECT * 170
FROM staff 180
WHERE dept < 77 230
)AS t1
WHERE id < 300
)AS t2
WHERE job LIKE 'C%'
)AS t3
WHERE salary < 18000
)AS t4
WHERE years < 5;
Figure 826, Nested fullselects
SELECT a.id ANSWER
,a.dept =========================
,a.salary ID DEPT SALARY AVG_DEPT
,DEC(b.avgsal,7,2) AS avg_dept -- ---- -------- --------
FROM staff a 10 20 18357.50 16071.52
LEFT OUTER JOIN 20 20 78171.25 16071.52
(SELECT dept AS dept 30 38 77506.75 -
,AVG(salary) AS avgsal
FROM staff
GROUP BY dept
HAVING AVG(salary) > 16000
)AS b
ON a.dept = b.dept
WHERE a.id < 40
ORDER BY a.id;
Figure 827, Join fullselect to real table
SELECT a.id ANSWER
,a.dept =========================
,a.salary ID DEPT SALARY DEPTSAL
,b.deptsal -- ---- -------- --------
FROM staff a 10 20 18357.50 64286.10
,TABLE 20 20 78171.25 64286.10
(SELECT b.dept 30 38 77506.75 77285.55
,SUM(b.salary) AS deptsal
FROM staff b
WHERE b.dept = a.dept
GROUP BY b.dept
)AS b
WHERE a.id < 40
ORDER BY a.id;
Figure 828, Fullselect with external table reference
SELECT a.id ANSWER
,a.dept =========================
,a.salary ID DEPT SALARY DEPTSAL
,b.deptsal -- ---- -------- --------
FROM staff a 10 20 18357.50 64286.10
,(SELECT b.dept 20 20 78171.25 64286.10
,SUM(b.salary) AS deptsal 30 38 77506.75 77285.55
FROM staff b
GROUP BY b.dept
)AS b
WHERE a.id < 40
AND b.dept = a.dept
ORDER BY a.id;
Figure 829, Fullselect without external table reference
SELECT id ANSWER
,salary ====================
,(SELECT MAX(salary) ID SALARY MAXSAL
FROM staff -- -------- --------
) AS maxsal 10 18357.50 22959.20
FROM staff a 20 78171.25 22959.20
WHERE id < 60 30 77506.75 22959.20
ORDER BY id; 40 18006.00 22959.20
50 20659.80 22959.20
Figure 830, Use an uncorrelated Full-Select in a SELECT list
SELECT id ANSWER
,salary ====================
,(SELECT MAX(salary) ID SALARY MAXSAL
FROM staff b -- -------- --------
WHERE a.dept = b.dept 10 18357.50 18357.50
) AS maxsal 20 78171.25 18357.50
FROM staff a 30 77506.75 18006.00
WHERE id < 60 40 18006.00 18006.00
ORDER BY id; 50 20659.80 20659.80
Figure 831, Use a correlated Full-Select in a SELECT list
SELECT id ANSWER
,dept ==================================
,salary ID DEPT SALARY 4 5
,(SELECT MAX(salary) -- ---- -------- -------- --------
FROM staff b 10 20 18357.50 18357.50 22959.20
WHERE b.dept = a.dept) 20 20 78171.25 18357.50 22959.20
,(SELECT MAX(salary) 30 38 77506.75 18006.00 22959.20
FROM staff) 40 38 18006.00 18006.00 22959.20
FROM staff a 50 15 20659.80 20659.80 22959.20
WHERE id < 60
ORDER BY id;
Figure 832, Use correlated and uncorrelated Full-Selects in a SELECT list
INSERT INTO staff
SELECT id + 1
,(SELECT MIN(name)
FROM staff)
,(SELECT dept
FROM staff s2
WHERE s2.id = s1.id - 100)
,'A',1,2,3
FROM staff s1
WHERE id =
(SELECT MAX(id)
FROM staff);
Figure 833, Fullselect in INSERT
UPDATE staff a ANSWER: SALARY
SET salary = ======= =================
(SELECT AVG(salary)+ 2000 ID DEPT BEFORE AFTER
FROM staff) -- ---- -------- --------
WHERE id < 60; 10 20 18357.50 18675.64
20 20 78171.25 18675.64
30 38 77506.75 18675.64
40 38 18006.00 18675.64
50 15 20659.80 18675.64
Figure 834, Use uncorrelated Full-Select to give workers company AVG salary (+$2000)
UPDATE staff a ANSWER: SALARY
SET salary = ======= =================
(SELECT AVG(salary) + 2000 ID DEPT BEFORE AFTER
FROM staff b -- ---- -------- --------
WHERE a.dept = b.dept ) 10 20 18357.50 18071.52
WHERE id < 60; 20 20 78171.25 18071.52
30 38 77506.75 17457.11
40 38 18006.00 17457.11
50 15 20659.80 17482.33
Figure 835, Use correlated Full-Select to give workers department AVG salary (+$2000)
UPDATE staff a
SET (salary,years) =
(SELECT AVG(salary) + 2000
,MAX(years)
FROM staff b
WHERE a.dept = b.dept )
WHERE id < 60;
Figure 836, Update two fields by referencing Full-Select
Figure 837, Declared Global Temporary Table syntax
DECLARE GLOBAL TEMPORARY TABLE session.fred
(dept SMALLINT NOT NULL
,avg_salary DEC(7,2) NOT NULL
,num_emps SMALLINT NOT NULL)
ON COMMIT DELETE ROWS;
Figure 838, Declare Global Temporary Table - define columns
DECLARE GLOBAL TEMPORARY TABLE session.fred
LIKE staff INCLUDING COLUMN DEFAULTS
WITH REPLACE
ON COMMIT PRESERVE ROWS;
Figure 839, Declare Global Temporary Table - like another table
DECLARE GLOBAL TEMPORARY TABLE session.fred AS
(SELECT dept
,MAX(id) AS max_id
,SUM(salary) AS sum_sal
FROM staff
WHERE name <> 'IDIOT'
GROUP BY dept)
DEFINITION ONLY
WITH REPLACE;
Figure 840, Declare Global Temporary Table - like query output
DECLARE GLOBAL TEMPORARY TABLE session.fred
LIKE staff INCLUDING COLUMN DEFAULTS
WITH REPLACE ON COMMIT DELETE ROWS;
CREATE UNIQUE INDEX session.fredx ON Session.fred (id);
INSERT INTO session.fred
SELECT *
FROM staff
WHERE id < 200;
ANSWER
SELECT COUNT(*) ======
FROM session.fred; 19
COMMIT;
ANSWER
SELECT COUNT(*) ======
FROM session.fred; 0
Figure 841, Temporary table with index
DECLARE GLOBAL TEMPORARY TABLE session.fred
(dept SMALLINT NOT NULL
,avg_salary DEC(7,2) NOT NULL
,num_emps SMALLINT NOT NULL)
ON COMMIT DELETE ROWS;
INSERT INTO session.fred
SELECT dept
,AVG(salary)
,COUNT(*)
FROM staff
GROUP BY dept;
ANSWER
SELECT COUNT(*) ======
FROM session.fred; 8
DROP TABLE session.fred;
DECLARE GLOBAL TEMPORARY TABLE session.fred
(dept SMALLINT NOT NULL)
ON COMMIT DELETE ROWS;
ANSWER
SELECT COUNT(*) ======
FROM session.fred; 0
Figure 842, Dropping a temporary table
CREATE USER TEMPORARY TABLESPACE FRED
MANAGED BY DATABASE
USING (FILE 'C:\DB2\TEMPFRED\FRED1' 1000
,FILE 'C:\DB2\TEMPFRED\FRED2' 1000
,FILE 'C:\DB2\TEMPFRED\FRED3' 1000);
GRANT USE OF TABLESPACE FRED TO PUBLIC;
Figure 843, Create USER TEMPORARY tablespace
HIERARCHY AAA
+---------------+ |
|PKEY |CKEY |NUM| +-----+-----+
|-----|-----|---| | | |
|AAA |BBB | 1| BBB CCC DDD
|AAA |CCC | 5| | |
|AAA |DDD | 20| +-+ +-+--+
|CCC |EEE | 33| | | |
|DDD |EEE | 44| EEE FFF
|DDD |FFF | 5| |
|FFF |GGG | 5| |
+---------------+ GGG
Figure 844, Sample Table description - Recursion
WITH parent (pkey, ckey) AS ANSWER
(SELECT pkey, ckey ========= PROCESSING
FROM hierarchy PKEY CKEY SEQUENCE
WHERE pkey = 'AAA' ---- ---- ==========
UNION ALL AAA BBB < 1st pass
SELECT C.pkey, C.ckey AAA CCC ""
FROM hierarchy C AAA DDD ""
,parent P CCC EEE < 2nd pass
WHERE P.ckey = C.pkey DDD EEE < 3rd pass
) DDD FFF ""
SELECT pkey, ckey FFF GGG < 4th pass
FROM parent;
Figure 845, SQL that does Recursion
Figure 846, Recursive processing sequence
CREATE TABLE hierarchy
(pkey CHAR(03) NOT NULL
,ckey CHAR(03) NOT NULL
,num SMALLINT NOT NULL
,PRIMARY KEY(pkey, ckey)
,CONSTRAINT dt1 CHECK (pkey <> ckey)
,CONSTRAINT dt2 CHECK (num > 0));
COMMIT;
CREATE UNIQUE INDEX hier_x1 ON hierarchy
(ckey, pkey);
COMMIT;
INSERT INTO hierarchy VALUES
('AAA','BBB', 1),
('AAA','CCC', 5),
('AAA','DDD',20),
('CCC','EEE',33),
('DDD','EEE',44),
('DDD','FFF', 5),
('FFF','GGG', 5);
COMMIT;
Figure 847, Sample Table DDL - Recursion
WITH parent (ckey) AS ANSWER HIERARCHY
(SELECT ckey ====== +---------------+
FROM hierarchy CKEY |PKEY |CKEY |NUM|
WHERE pkey = 'AAA' ---- |-----|-----|---|
UNION ALL BBB |AAA |BBB | 1|
SELECT C.ckey CCC |AAA |CCC | 5|
FROM hierarchy C DDD |AAA |DDD | 20|
,parent P EEE |CCC |EEE | 33|
WHERE P.ckey = C.pkey EEE |DDD |EEE | 44|
) FFF |DDD |FFF | 5|
SELECT ckey GGG |FFF |GGG | 5|
FROM parent; +---------------+
Figure 848, List of children of AAA
WITH parent (ckey) AS ANSWER HIERARCHY
(SELECT DISTINCT pkey ====== +---------------+
FROM hierarchy CKEY |PKEY |CKEY |NUM|
WHERE pkey = 'AAA' ---- |-----|-----|---|
UNION ALL AAA |AAA |BBB | 1|
SELECT C.ckey BBB |AAA |CCC | 5|
FROM hierarchy C CCC |AAA |DDD | 20|
,parent P DDD |CCC |EEE | 33|
WHERE P.ckey = C.pkey EEE |DDD |EEE | 44|
) EEE |DDD |FFF | 5|
SELECT ckey FFF |FFF |GGG | 5|
FROM parent; GGG +---------------+
Figure 849, List all children of AAA
WITH parent (ckey) AS ANSWER HIERARCHY
(SELECT DISTINCT pkey ====== +---------------+
FROM hierarchy CKEY |PKEY |CKEY |NUM|
WHERE pkey = 'AAA' ---- |-----|-----|---|
UNION ALL AAA |AAA |BBB | 1|
SELECT C.ckey BBB |AAA |CCC | 5|
FROM hierarchy C CCC |AAA |DDD | 20|
,parent P DDD |CCC |EEE | 33|
WHERE P.ckey = C.pkey EEE |DDD |EEE | 44|
) FFF |DDD |FFF | 5|
SELECT DISTINCT ckey GGG |FFF |GGG | 5|
FROM parent; +---------------+
Figure 850, List distinct children of AAA
WITH parent (ckey) AS ANSWER HIERARCHY
(SELECT DISTINCT pkey ====== +---------------+
FROM hierarchy CKEY |PKEY |CKEY |NUM|
WHERE pkey = 'AAA' ---- |-----|-----|---|
UNION ALL AAA |AAA |BBB | 1|
SELECT C.ckey BBB |AAA |CCC | 5|
FROM hierarchy C CCC |AAA |DDD | 20|
,parent P DDD |CCC |EEE | 33|
WHERE P.ckey = C.pkey EEE |DDD |EEE | 44|
), FFF |DDD |FFF | 5|
distinct_parent (ckey) AS GGG |FFF |GGG | 5|
(SELECT DISTINCT ckey +---------------+
FROM parent
)
SELECT ckey
FROM distinct_parent;
Figure 851, List distinct children of AAA
WITH parent (ckey, lvl) AS ANSWER AAA
(SELECT DISTINCT pkey, 0 ======== |
FROM hierarchy CKEY LVL +-----+-----+
WHERE pkey = 'AAA' ---- --- | | |
UNION ALL AAA 0 BBB CCC DDD
SELECT C.ckey, P.lvl +1 BBB 1 | |
FROM hierarchy C CCC 1 +-+ +-+--+
,parent P DDD 1 | | |
WHERE P.ckey = C.pkey EEE 2 EEE FFF
) EEE 2 |
SELECT ckey, lvl FFF 2 |
FROM parent; GGG 3 GGG
Figure 852, Show item level in hierarchy
WITH parent (ckey, lvl) AS ANSWER HIERARCHY
(SELECT DISTINCT pkey, 0 ======== +---------------+
FROM hierarchy CKEY LVL |PKEY |CKEY |NUM|
WHERE pkey = 'AAA' ---- --- |-----|-----|---|
UNION ALL AAA 0 |AAA |BBB | 1|
SELECT C.ckey, P.lvl +1 BBB 1 |AAA |CCC | 5|
FROM hierarchy C CCC 1 |AAA |DDD | 20|
,parent P DDD 1 |CCC |EEE | 33|
WHERE P.ckey = C.pkey EEE 2 |DDD |EEE | 44|
) EEE 2 |DDD |FFF | 5|
SELECT ckey, lvl FFF 2 |FFF |GGG | 5|
FROM parent +---------------+
WHERE lvl < 3;
Figure 853, Select rows where LEVEL < 3
WITH parent (ckey, lvl) AS ANSWER AAA
(SELECT DISTINCT pkey, 0 ======== |
FROM hierarchy CKEY LVL +-----+-----+
WHERE pkey = 'AAA' ---- --- | | |
UNION ALL AAA 0 BBB CCC DDD
SELECT C.ckey, P.lvl +1 BBB 1 | |
FROM hierarchy C CCC 1 +-+ +-+--+
,parent P DDD 1 | | |
WHERE P.ckey = C.pkey EEE 2 EEE FFF
AND P.lvl+1 < 3 EEE 2 |
) FFF 2 |
SELECT ckey, lvl GGG
FROM parent;
Figure 854, Select rows where LEVEL < 3
WITH parent (ckey, lvl) AS ANSWER HIERARCHY
(SELECT DISTINCT pkey, 0 ======== +---------------+
FROM hierarchy CKEY LVL |PKEY |CKEY |NUM|
WHERE pkey = 'AAA' ---- --- |-----|-----|---|
UNION ALL EEE 2 |AAA |BBB | 1|
SELECT C.ckey, P.lvl +1 EEE 2 |AAA |CCC | 5|
FROM hierarchy C FFF 2 |AAA |DDD | 20|
,parent P |CCC |EEE | 33|
WHERE P.ckey = C.pkey |DDD |EEE | 44|
AND P.lvl+1 < 3 |DDD |FFF | 5|
) |FFF |GGG | 5|
SELECT ckey, lvl +---------------+
FROM parent
WHERE lvl = 2;
Figure 855, Select rows where LEVEL = 2
WITH children (kkey, lvl) AS ANSWER AAA
(SELECT ckey, 1 ======== |
FROM hierarchy KKEY LVL +-----+-----+
WHERE pkey = 'DDD' ---- --- | | |
UNION ALL AAA -1 BBB CCC DDD
SELECT H.ckey, C.lvl + 1 EEE 1 | |
FROM hierarchy H FFF 1 +-+ +-+--+
,children C GGG 2 | | |
WHERE H.pkey = C.kkey EEE FFF
) |
,parents (kkey, lvl) AS |
(SELECT pkey, -1 GGG
FROM hierarchy
WHERE ckey = 'DDD'
UNION ALL
SELECT H.pkey, P.lvl - 1
FROM hierarchy H
,parents P
WHERE H.ckey = P.kkey
)
SELECT kkey ,lvl
FROM children
UNION ALL
SELECT kkey ,lvl
FROM parents;
Figure 856, Find all children and parents of DDD
WITH temp1 (n1) AS ANSWER
(SELECT id ======
FROM staff N1
WHERE id = 10 --
UNION ALL warn
SELECT n1 +10 10
FROM temp1 20
WHERE n1 < 50 30
) 40
SELECT * 50
FROM temp1;
Figure 857, Recursion - with warning message
WITH temp1 (n1) AS ANSWER
(SELECT INT(id) ======
FROM staff N1
WHERE id = 10 --
UNION ALL 10
SELECT n1 +10 20
FROM temp1 30
WHERE n1 < 50 40
) 50
SELECT *
FROM temp1;
Figure 858, Recursion - without warning message
DIVERGENT CONVERGENT RECURSIVE BALANCED UNBALANCED
========= ========== ========= ======== ==========
AAA AAA AAA<--+ AAA AAA
| | | | | |
+-+-+ +-+-+ +-+-+ | +-+-+ +-+-+
| | | | | | | | | | |
BBB CCC BBB CCC BBB CCC>+ BBB CCC BBB CCC
| | | | | | |
+-+-+ +-+-+-+ +-+-+ | +---+ +-+-+
| | | | | | | | | | |
DDD EEE DDD EEE DDD EEE DDD EEE FFF DDD EEE
Figure 859, Hierarchy Flavours
OBJECTS_RELATES AAA
+---------------------+ |
|KEYO |PKEY |NUM|PRICE| +-----+-----+
|-----|-----|---|-----| | | |
|AAA | | | $10| BBB CCC DDD
|BBB |AAA | 1| $21| |
|CCC |AAA | 5| $23| +--+--+
|DDD |AAA | 20| $25| | |
|EEE |DDD | 44| $33| EEE FFF
|FFF |DDD | 5| $34| |
|GGG |FFF | 5| $44| |
+---------------------+ GGG
Figure 860, Divergent Hierarchy - Table and Layout
OBJECTS RELATIONSHIPS AAA
+-----------+ +---------------+ |
|KEYO |PRICE| |PKEY |CKEY |NUM| +-----+-----+
|-----|-----| |-----|-----|---| | | |
|AAA | $10| |AAA |BBB | 1| BBB CCC DDD
|BBB | $21| |AAA |CCC | 5| | |
|CCC | $23| |AAA |DDD | 20| +-+ +-+--+
|DDD | $25| |CCC |EEE | 33| | | |
|EEE | $33| |DDD |EEE | 44| EEE FFF
|FFF | $34| |DDD |FFF | 5| |
|GGG | $44| |FFF |GGG | 5| |
+-----------+ +---------------+ GGG
Figure 861, Convergent Hierarchy - Tables and Layout
OBJECTS RELATIONSHIPS AAA <------+
+-----------+ +---------------+ | |
|KEYO |PRICE| |PKEY |CKEY |NUM| +-----+-----+ |
|-----|-----| |-----|-----|---| | | | |
|AAA | $10| |AAA |BBB | 1| BBB CCC DDD>-+
|BBB | $21| |AAA |CCC | 5| | |
|CCC | $23| |AAA |DDD | 20| +-+ +-+--+
|DDD | $25| |CCC |EEE | 33| | | |
|EEE | $33| |DDD |AAA | 99| EEE FFF
|FFF | $34| |DDD |FFF | 5| |
|GGG | $44| |DDD |EEE | 44| |
+-----------+ |FFF |GGG | 5| GGG
+---------------+
Figure 862, Recursive Hierarchy - Tables and Layout
AAA << Balanced hierarchy AAA
| Unbalanced hierarchy >> |
+-----+-----+ +---+----+
| | | | | |
BBB CCC DDD | CCC DDD
| | | | | |
| | +-+-+ | +-+ +-+-+
| | | | | | | |
EEE FFF GGG HHH FFF GGG HHH
|
|
III
Figure 863, Balanced and Unbalanced Hierarchies
TROUBLE AAA <------+
+---------+ | |
|PKEY|CKEY| +-----+-----+ |
|----|----| | | | |
|AAA |BBB | BBB CCC DDD>-+
|AAA |CCC | | |
|AAA |DDD | +-+ +-+--+
|CCC |EEE | | | |
|DDD |AAA | <=== This row EEE FFF
|DDD |FFF | points back to |
|DDD |EEE | the hierarchy |
|FFF |GGG | parent. GGG
+---------+
Figure 864, Recursive Hierarchy - Sample Table and Layout
CREATE TABLE trouble
(pkey CHAR(03) NOT NULL
,ckey CHAR(03) NOT NULL);
CREATE UNIQUE INDEX tble_x1 ON trouble (pkey, ckey);
CREATE UNIQUE INDEX tble_x2 ON trouble (ckey, pkey);
INSERT INTO trouble VALUES
('AAA','BBB'),
('AAA','CCC'),
('AAA','DDD'),
('CCC','EEE'),
('DDD','AAA'),
('DDD','EEE'),
('DDD','FFF'),
('FFF','GGG');
Figure 865, Sample Table DDL - Recursive Hierarchy
WITH parent (pkey, ckey, lvl) AS ANSWER TROUBLE
(SELECT DISTINCT ============= +---------+
pkey PKEY CKEY LVL |PKEY|CKEY|
,pkey ---- ---- --- |----|----|
,0 AAA AAA 0 |AAA |BBB |
FROM trouble AAA BBB 1 |AAA |CCC |
WHERE pkey = 'AAA' AAA CCC 1 |AAA |DDD |
UNION ALL AAA DDD 1 |CCC |EEE |
SELECT C.pkey CCC EEE 2 |DDD |AAA |
,C.ckey DDD AAA 2 |DDD |FFF |
,P.lvl + 1 DDD EEE 2 |DDD |EEE |
FROM trouble C DDD FFF 2 |FFF |GGG |
,parent P AAA BBB 3 +---------+
WHERE P.ckey = C.pkey AAA CCC 3
AND P.lvl + 1 < 4 AAA DDD 3
) FFF GGG 3
SELECT *
FROM parent;
Figure 866, Stop Recursive SQL after "n" levels
CREATE FUNCTION LOCATE_BLOCK(searchstr VARCHAR(30000)
,lookinstr VARCHAR(30000))
RETURNS INTEGER
BEGIN ATOMIC
DECLARE lookinlen, searchlen INT;
DECLARE locatevar, returnvar INT DEFAULT 0;
DECLARE beginlook INT DEFAULT 1;
SET lookinlen = LENGTH(lookinstr);
SET searchlen = LENGTH(searchstr);
WHILE locatevar = 0 AND
beginlook <= lookinlen DO
SET locatevar = LOCATE(searchstr,SUBSTR(lookinstr
,beginlook
,searchlen));
SET beginlook = beginlook + searchlen;
SET returnvar = returnvar + 1;
END WHILE;
IF locatevar = 0 THEN
SET returnvar = 0;
END IF;
RETURN returnvar;
END
Figure 867, LOCATE_BLOCK user defined function
SELECT id ANSWER
,name =================
,LOCATE('th',name) AS l1 ID NAME L1 L2
,LOCATE_BLOCK('th',name) AS l2 --- ------- -- --
FROM staff 70 Rothman 3 2
WHERE LOCATE('th',name) > 1; 220 Smith 4 0
Figure 868, LOCATE_BLOCK function example
WITH parent (pkey, ckey, lvl, path, loop) AS
(SELECT DISTINCT
pkey
,pkey ANSWER
,0 ===============================
,VARCHAR(pkey,20) PKEY CKEY LVL PATH LOOP
,0 ---- ---- --- ------------ ----
FROM trouble AAA AAA 0 AAA 0
WHERE pkey = 'AAA' AAA BBB 1 AAABBB 0
UNION ALL AAA CCC 1 AAACCC 0
SELECT C.pkey AAA DDD 1 AAADDD 0
,C.ckey CCC EEE 2 AAACCCEEE 0
,P.lvl + 1 DDD AAA 2 AAADDDAAA 1
,P.path || C.ckey DDD EEE 2 AAADDDEEE 0
,LOCATE_BLOCK(C.ckey,P.path) DDD FFF 2 AAADDDFFF 0
FROM trouble C AAA BBB 3 AAADDDAAABBB 0
,parent P AAA CCC 3 AAADDDAAACCC 0
WHERE P.ckey = C.pkey AAA DDD 3 AAADDDAAADDD 2
AND P.lvl + 1 < 4 FFF GGG 3 AAADDDFFFGGG 0
)
SELECT *
FROM parent; TROUBLE
+---------+ AAA <------+
|PKEY|CKEY| | |
|----|----| +-----+-----+ |
|AAA |BBB | | | | |
|AAA |CCC | BBB CCC DDD>-+
|AAA |DDD | | |
|CCC |EEE | +-+ +-+--+
This row ===> |DDD |AAA | | | |
points back to |DDD |FFF | EEE FFF
the hierarchy |DDD |EEE | |
parent. |FFF |GGG | |
+---------+ GGG
Figure 869, Show path, and rows in loop
WITH parent (pkey, ckey, lvl, path) AS ANSWER
(SELECT DISTINCT ==========================
pkey PKEY CKEY LVL PATH
,pkey ---- ----- -- ------------
,0 AAA AAA 0 AAA
,VARCHAR(pkey,20) AAA BBB 1 AAABBB
FROM trouble AAA CCC 1 AAACCC
WHERE pkey = 'AAA' AAA DDD 1 AAADDD
UNION ALL CCC EEE 2 AAACCCEEE
SELECT C.pkey DDD EEE 2 AAADDDEEE
,C.ckey DDD FFF 2 AAADDDFFF
,P.lvl + 1 FFF GGG 3 AAADDDFFFGGG
,P.path || C.ckey
FROM trouble C
,parent P
WHERE P.ckey = C.pkey
AND LOCATE_BLOCK(C.ckey,P.path) = 0
)
SELECT *
FROM parent;
Figure 870, Use LOCATE_BLOCK function to stop recursion
WITH parent (pkey, ckey, lvl, path, loop) AS
(SELECT DISTINCT
pkey
,pkey
,0
,VARCHAR(pkey,20) ANSWER
,0 ===============================
FROM trouble PKEY CKEY LVL PATH LOOP
WHERE pkey = 'AAA' ---- ---- --- ------------ ----
UNION ALL AAA AAA 0 AAA 0
SELECT C.pkey AAA BBB 1 AAABBB 0
,C.ckey AAA CCC 1 AAACCC 0
,P.lvl + 1 AAA DDD 1 AAADDD 0
,P.path || C.ckey CCC EEE 2 AAACCCEEE 0
,LOCATE_BLOCK(C.ckey,P.path) DDD AAA 2 AAADDDAAA 1
FROM trouble C DDD EEE 2 AAADDDEEE 0
,parent P DDD FFF 2 AAADDDFFF 0
WHERE P.ckey = C.pkey FFF GGG 3 AAADDDFFFGGG 0
AND P.loop = 0
)
SELECT *
FROM parent;
Figure 871, Use LOCATE_BLOCK function to stop recursion
WITH parent (pkey, ckey, lvl, path, loop) AS ANSWER
(SELECT DISTINCT =========
pkey PKEY CKEY
,pkey ---- ----
,0 DDD AAA
,VARCHAR(pkey,20)
,0
FROM trouble
WHERE pkey = 'AAA'
UNION ALL
SELECT C.pkey
,C.ckey TROUBLE
,P.lvl + 1 +---------+
,P.path || C.ckey |PKEY|CKEY|
,LOCATE_BLOCK(C.ckey,P.path) |----|----|
FROM trouble C |AAA |BBB |
,parent P |AAA |CCC |
WHERE P.ckey = C.pkey |AAA |DDD |
AND P.loop = 0 |CCC |EEE |
) This row ===> |DDD |AAA |
SELECT pkey points back to |DDD |FFF |
,ckey the hierarchy |DDD |EEE |
FROM parent parent. |FFF |GGG |
WHERE loop > 0; +---------+
Figure 872,List rows that point back to a parent
DECLARE GLOBAL TEMPORARY TABLE SESSION.del_list
(pkey CHAR(03) NOT NULL
,ckey CHAR(03) NOT NULL)
ON COMMIT PRESERVE ROWS;
INSERT INTO SESSION.del_list
WITH parent (pkey, ckey, lvl, path, loop) AS
(SELECT DISTINCT
pkey
,pkey
,0 TROUBLE
,VARCHAR(pkey,20) +---------+
,0 |PKEY|CKEY|
FROM trouble |----|----|
WHERE pkey = 'AAA' |AAA |BBB |
UNION ALL |AAA |CCC |
SELECT C.pkey |AAA |DDD |
,C.ckey |CCC |EEE |
,P.lvl + 1 This row ===> |DDD |AAA |
,P.path || C.ckey points back to |DDD |FFF |
,LOCATE_BLOCK(C.ckey,P.path) the hierarchy |DDD |EEE |
FROM trouble C parent. |FFF |GGG |
,parent P +---------+
WHERE P.ckey = C.pkey
AND P.loop = 0 AAA <------+
) | |
SELECT pkey +-----+-----+ |
,ckey | | | |
FROM parent BBB CCC DDD>-+
WHERE loop > 0; | |
+-+ +-+--+
DELETE | | |
FROM trouble EEE FFF
WHERE (pkey,ckey) IN |
(SELECT pkey, ckey |
FROM SESSION.del_list); GGG
Figure 873, Delete rows that loop back to a parent
CREATE TRIGGER TBL_INS TROUBLE
NO CASCADE BEFORE INSERT ON trouble +---------+
REFERENCING NEW AS NNN This trigger |PKEY|CKEY|
FOR EACH ROW MODE DB2SQL would reject |----|----|
WITH temp (pkey, ckey) AS insertion of |AAA |BBB |
(VALUES (NNN.pkey this row. |AAA |CCC |
,NNN.ckey) | |AAA |DDD |
UNION ALL | |CCC |EEE |
SELECT TTT.pkey +---> |DDD |AAA |
,CASE |DDD |FFF |
WHEN TTT.ckey = TBL.pkey |DDD |EEE |
THEN RAISE_ERROR('70001','LOOP FOUND') |FFF |GGG |
ELSE TBL.ckey +---------+
END
FROM trouble TBL
,temp TTT
WHERE TTT.ckey = TBL.pkey
)
SELECT *
FROM temp;
Figure 874, INSERT trigger
CREATE TRIGGER TBL_UPD
NO CASCADE BEFORE UPDATE OF pkey, ckey ON trouble
REFERENCING NEW AS NNN
FOR EACH ROW MODE DB2SQL
WITH temp (pkey, ckey) AS
(VALUES (NNN.pkey
,NNN.ckey)
UNION ALL
SELECT TTT.pkey
,CASE
WHEN TTT.ckey = TBL.pkey
THEN RAISE_ERROR('70001','LOOP FOUND')
ELSE TBL.ckey
END
FROM trouble TBL
,temp TTT
WHERE TTT.ckey = TBL.pkey
)
SELECT *
FROM temp;
Figure 875, UPDATE trigger
INSERT INTO trouble VALUES('GGG','AAA');
UPDATE trouble SET ckey = 'AAA' WHERE pkey = 'FFF';
UPDATE trouble SET pkey = 'GGG' WHERE ckey = 'DDD';
Figure 876, Invalid DML statements
HIERARCHY#1 EXPLODED#1
AAA +--------------------+ +-------------+
| |KEYY|PKEY|DATA | |PKEY|CKEY|LVL|
BBB |----|----|----------| |----|----|---|
| |AAA |AAA |SOME DATA | |AAA |AAA | 0|
+-----+ |BBB |AAA |MORE DATA | |AAA |BBB | 1|
| | |CCC |BBB |MORE JUNK | |AAA |CCC | 2|
CCC EEE |DDD |CCC |MORE JUNK | |AAA |DDD | 3|
| |EEE |BBB |JUNK DATA | |AAA |EEE | 2|
DDD +--------------------+ |BBB |BBB | 0|
|BBB |CCC | 1|
|BBB |DDD | 2|
|BBB |EEE | 1|
|CCC |CCC | 0|
|CCC |DDD | 1|
|DDD |DDD | 0|
|EEE |EEE | 0|
+-------------+
Figure 877, Data Hierarchy, with normalized and exploded representations
CREATE TABLE hierarchy#1
(keyy CHAR(3) NOT NULL
,pkey CHAR(3) NOT NULL
,data VARCHAR(10)
,CONSTRAINT hierarchy11 PRIMARY KEY(keyy)
,CONSTRAINT hierarchy12 FOREIGN KEY(pkey)
REFERENCES hierarchy#1 (keyy) ON DELETE CASCADE);
CREATE TRIGGER HIR#1_UPD
NO CASCADE BEFORE UPDATE OF pkey ON hierarchy#1
REFERENCING NEW AS NNN
OLD AS OOO
FOR EACH ROW MODE DB2SQL
WHEN (NNN.pkey <> OOO.pkey)
SIGNAL SQLSTATE '70001' ('CAN NOT UPDATE pkey');
Figure 878, Hierarchy table that does not allow updates to PKEY
CREATE TABLE exploded#1
(pkey CHAR(4) NOT NULL
,ckey CHAR(4) NOT NULL
,lvl SMALLINT NOT NULL
,PRIMARY KEY(pkey,ckey));
Figure 879, Exploded table CREATE statement
CREATE TRIGGER EXP#1_DEL
AFTER DELETE ON hierarchy#1
REFERENCING OLD AS OOO
FOR EACH ROW MODE DB2SQL
DELETE
FROM exploded#1
WHERE ckey = OOO.keyy;
Figure 880, Trigger to maintain exploded table after delete in hierarchy table
CREATE TRIGGER EXP#1_INS HIERARCHY#1 EXPLODED#1
AFTER INSERT ON hierarchy#1 +--------------+ +-------------+
REFERENCING NEW AS NNN |KEYY|PKEY|DATA| |PKEY|CKEY|LVL|
FOR EACH ROW MODE DB2SQL |----|----|----| |----|----|---|
INSERT |AAA |AAA |S...| |AAA |AAA | 0|
INTO exploded#1 |BBB |AAA |M...| |AAA |BBB | 1|
WITH temp(pkey, ckey, lvl) AS |CCC |BBB |M...| |AAA |CCC | 2|
(VALUES (NNN.keyy |DDD |CCC |M...| |AAA |DDD | 3|
,NNN.keyy |EEE |BBB |J...| |AAA |EEE | 2|
,0) +--------------+ |BBB |BBB | 0|
UNION ALL |BBB |CCC | 1|
SELECT N.pkey |BBB |DDD | 2|
,NNN.keyy |BBB |EEE | 1|
,T.lvl +1 |CCC |CCC | 0|
FROM temp T |CCC |DDD | 1|
,hierarchy#1 N |DDD |DDD | 0|
WHERE N.keyy = T.pkey |EEE |EEE | 0|
AND N.keyy <> N.pkey +-------------+
)
SELECT *
FROM temp;
Figure 881, Trigger to maintain exploded table after insert in hierarchy table
SELECT *
FROM exploded#1
WHERE pkey = :host-var
ORDER BY pkey
,ckey
,lvl;
Figure 882, Querying the exploded table
CREATE TABLE hierarchy#2
(keyy CHAR(3) NOT NULL
,pkey CHAR(3) NOT NULL
,data VARCHAR(10)
,CONSTRAINT NO_loopS21 PRIMARY KEY(keyy)
,CONSTRAINT NO_loopS22 FOREIGN KEY(pkey)
REFERENCES hierarchy#2 (keyy) ON DELETE CASCADE
ON UPDATE RESTRICT);
Figure 883, Hierarchy table that allows updates to PKEY
CREATE TRIGGER HIR#2_UPD HIERARCHY#2
NO CASCADE BEFORE UPDATE OF pkey ON hierarchy#2 +--------------+
REFERENCING NEW AS NNN |KEYY|PKEY|DATA|
OLD AS OOO |----|----|----|
FOR EACH ROW MODE DB2SQL |AAA |AAA |S...|
WHEN (NNN.pkey <> OOO.pkey |BBB |AAA |M...|
AND NNN.pkey <> NNN.keyy) |CCC |BBB |M...|
WITH temp (keyy, pkey) AS |DDD |CCC |M...|
(VALUES (NNN.keyy |EEE |BBB |J...|
,NNN.pkey) +--------------+
UNION ALL
SELECT LP2.keyy
,CASE
WHEN LP2.keyy = NNN.keyy
THEN RAISE_ERROR('70001','LOOP FOUND')
ELSE LP2.pkey
END
FROM hierarchy#2 LP2
,temp TMP
WHERE TMP.pkey = LP2.keyy
AND TMP.keyy <> TMP.pkey
)
SELECT *
FROM temp;
Figure 884, Trigger to check for recursive data structures before update of PKEY
CREATE TABLE exploded#2
(pkey CHAR(4) NOT NULL
,ckey CHAR(4) NOT NULL
,lvl SMALLINT NOT NULL
,PRIMARY KEY(pkey,ckey));
Figure 885, Exploded table CREATE statement
CREATE TRIGGER EXP#2_DEL
AFTER DELETE ON hierarchy#2
REFERENCING OLD AS OOO
FOR EACH ROW MODE DB2SQL
DELETE
FROM exploded#2
WHERE ckey = OOO.keyy;
Figure 886, Trigger to maintain exploded table after delete in hierarchy table
CREATE TRIGGER EXP#2_INS HIERARCHY#2 EXPLODED#2
AFTER INSERT ON hierarchy#2 +--------------+ +-------------+
REFERENCING NEW AS NNN |KEYY|PKEY|DATA| |PKEY|CKEY|LVL|
FOR EACH ROW MODE DB2SQL |----|----|----| |----|----|---|
INSERT |AAA |AAA |S...| |AAA |AAA | 0|
INTO exploded#2 |BBB |AAA |M...| |AAA |BBB | 1|
WITH temp(pkey, ckey, lvl) AS |CCC |BBB |M...| |AAA |CCC | 2|
(SELECT NNN.keyy |DDD |CCC |M...| |AAA |DDD | 3|
,NNN.keyy |EEE |BBB |J...| |AAA |EEE | 2|
,0 +--------------+ |BBB |BBB | 0|
FROM hierarchy#2 |BBB |CCC | 1|
WHERE keyy = NNN.keyy |BBB |DDD | 2|
UNION ALL |BBB |EEE | 1|
SELECT N.pkey |CCC |CCC | 0|
,NNN.keyy |CCC |DDD | 1|
,T.lvl +1 |DDD |DDD | 0|
FROM temp T |EEE |EEE | 0|
,hierarchy#2 N +-------------+
WHERE N.keyy = T.pkey
AND N.keyy <> N.pkey
)
SELECT *
FROM temp;
Figure 887, Trigger to maintain exploded table after insert in hierarchy table
CREATE TRIGGER EXP#2_UPD
AFTER UPDATE OF pkey ON hierarchy#2
REFERENCING OLD AS OOO
NEW AS NNN
FOR EACH ROW MODE DB2SQL
BEGIN ATOMIC
DELETE
FROM exploded#2
WHERE ckey IN
(SELECT ckey
FROM exploded#2
WHERE pkey = OOO.keyy);
INSERT
INTO exploded#2
WITH temp1(ckey) AS
(VALUES (NNN.keyy)
UNION ALL
SELECT N.keyy
FROM temp1 T
,hierarchy#2 N
WHERE N.pkey = T.ckey
AND N.pkey <> N.keyy
)
Figure 888, Trigger to run after update of PKEY in hierarchy table (part 1 of 2)
,temp2(pkey, ckey, lvl) AS
(SELECT ckey
,ckey
,0
FROM temp1
UNION ALL
SELECT N.pkey
,T.ckey
,T.lvl +1
FROM temp2 T
,hierarchy#2 N
WHERE N.keyy = T.pkey
AND N.keyy <> N.pkey
)
SELECT *
FROM temp2;
END
Figure 889, Trigger to run after update of PKEY in hierarchy table (part 2 of 2)
SELECT *
FROM exploded#2
WHERE pkey = :host-var
ORDER BY pkey
,ckey
,lvl;
Figure 890, Querying the exploded table
Figure 891, Create Trigger syntax
CREATE TABLE cust_balance
(cust# INTEGER NOT NULL
GENERATED ALWAYS AS IDENTITY
,status CHAR(2) NOT NULL
,balance DECIMAL(18,2) NOT NULL
,num_trans INTEGER NOT NULL
,cur_ts TIMESTAMP NOT NULL
,PRIMARY KEY (cust#));
CREATE TABLE cust_history
(cust# INTEGER NOT NULL
,trans# INTEGER NOT NULL
,balance DECIMAL(18,2) NOT NULL
,bgn_ts TIMESTAMP NOT NULL
,end_ts TIMESTAMP NOT NULL
,PRIMARY KEY (cust#, bgn_ts));
CREATE TABLE cust_trans
(min_cust# INTEGER
,max_cust# INTEGER
,rows_tot INTEGER NOT NULL
,change_val DECIMAL(18,2)
,change_type CHAR(1) NOT NULL
,cur_ts TIMESTAMP NOT NULL
,PRIMARY KEY (cur_ts));
Figure 892, Sample Tables
CREATE TRIGGER cust_bal_ins1
NO CASCADE BEFORE INSERT
ON cust_balance
REFERENCING NEW AS nnn
FOR EACH ROW
MODE DB2SQL
SET nnn.cur_ts = CURRENT TIMESTAMP
,nnn.num_trans = 1;
Figure 893, Before insert trigger - set values
CREATE TRIGGER cust_bal_upd1
NO CASCADE BEFORE UPDATE
ON cust_balance
REFERENCING NEW AS nnn
OLD AS ooo
FOR EACH ROW
MODE DB2SQL
SET nnn.cur_ts = CURRENT TIMESTAMP
,nnn.num_trans = ooo.num_trans + 1;
Figure 894, Before update trigger - set values
CREATE TRIGGER cust_bal_upd2
NO CASCADE BEFORE UPDATE OF balance
ON cust_balance
REFERENCING NEW AS nnn
OLD AS ooo
FOR EACH ROW
MODE DB2SQL
WHEN (ooo.balance - nnn.balance > 1000)
SIGNAL SQLSTATE VALUE '71001'
SET MESSAGE_TEXT = 'Cannot withdraw > 1000';
Figure 895, Before Trigger - flag error
CREATE TRIGGER cust_his_ins1
AFTER INSERT
ON cust_balance
REFERENCING NEW AS nnn
FOR EACH ROW
MODE DB2SQL
INSERT INTO cust_history VALUES
(nnn.cust#
,nnn.num_trans
,nnn.balance
,nnn.cur_ts
,'9999-12-31-24.00.00');
Figure 896, After Trigger - record insert
CREATE TRIGGER cust_his_upd1
AFTER UPDATE
ON cust_balance
REFERENCING OLD AS ooo
NEW AS nnn
FOR EACH ROW
MODE DB2SQL
BEGIN ATOMIC
UPDATE cust_history
SET end_ts = CURRENT TIMESTAMP
WHERE cust# = ooo.cust#
AND bgn_ts = ooo.cur_ts;
INSERT INTO cust_history VALUES
(nnn.cust#
,nnn.num_trans
,nnn.balance
,nnn.cur_ts
,'9999-12-31-24.00.00');
END
Figure 897, After Trigger - record update
CREATE TRIGGER cust_his_del1
AFTER DELETE
ON cust_balance
REFERENCING OLD AS ooo
FOR EACH ROW
MODE DB2SQL
UPDATE cust_history
SET end_ts = CURRENT TIMESTAMP
WHERE cust# = ooo.cust#
AND bgn_ts = ooo.cur_ts;
Figure 898, After Trigger - record delete
CREATE TRIGGER trans_his_ins1
AFTER INSERT
ON cust_balance
REFERENCING NEW_TABLE AS newtab
FOR EACH STATEMENT
MODE DB2SQL
INSERT INTO cust_trans
SELECT MIN(cust#)
,MAX(cust#)
,COUNT(*)
,SUM(balance)
,'I'
,CURRENT TIMESTAMP
FROM newtab;
Figure 899, After Trigger - record insert
CREATE TRIGGER trans_his_upd1
AFTER UPDATE
ON cust_balance
REFERENCING OLD_TABLE AS oldtab
NEW_TABLE AS newtab
FOR EACH STATEMENT
MODE DB2SQL
INSERT INTO cust_trans
SELECT MIN(nt.cust#)
,MAX(nt.cust#)
,COUNT(*)
,SUM(nt.balance - ot.balance)
,'U'
,CURRENT TIMESTAMP
FROM oldtab ot
,newtab nt
WHERE ot.cust# = nt.cust#;
Figure 900, After Trigger - record update
CREATE TRIGGER trans_his_del1
AFTER DELETE
ON cust_balance
REFERENCING OLD_TABLE AS oldtab
FOR EACH STATEMENT
MODE DB2SQL
INSERT INTO cust_trans
SELECT MIN(cust#)
,MAX(cust#)
,COUNT(*)
,SUM(balance)
,'D'
,CURRENT TIMESTAMP
FROM oldtab;
Figure 901, After Trigger - record delete
INSERT INTO cust_balance (status, balance) VALUES ('C',123.45);
INSERT INTO cust_balance (status, balance) VALUES ('C',000.00);
INSERT INTO cust_balance (status, balance) VALUES ('D', -1.00);
UPDATE cust_balance
SET balance = balance + 123
WHERE cust# <= 2;
UPDATE cust_balance
SET balance = balance * -1
WHERE cust# = -1;
UPDATE cust_balance
SET balance = balance - 123
WHERE cust# = 1;
DELETE
FROM cust_balance
WHERE cust# = 3;
Figure 902, Sample DML statements
Figure 903, Customer-balance table rows
Figure 904, Customer-history table rows
Figure 905, Customer-transaction table rows
CREATE TABLE customer_balance
(cust_id INTEGER
,cust_name VARCHAR(20)
,cust_sex CHAR(1)
,num_sales SMALLINT
,total_sales DECIMAL(12,2)
,master_cust_id INTEGER
,cust_insert_ts TIMESTAMP
,cust_update_ts TIMESTAMP);
CREATE TABLE us_sales
(invoice# INTEGER
,cust_id INTEGER
,sale_value DECIMAL(18,2)
,sale_insert_ts TIMESTAMP
,sale_update_ts TIMESTAMP);
Figure 906, Sample application tables
CREATE DISTINCT TYPE us_dollars AS decimal(18,2) WITH COMPARISONS;
Figure 907, Create US-dollars data type
CREATE TABLE customer_balance
(cust_id INTEGER NOT NULL
GENERATED ALWAYS AS IDENTITY
(START WITH 1
,INCREMENT BY 1
,NO CYCLE
,NO CACHE)
,cust_name VARCHAR(20) NOT NULL
,cust_sex CHAR(1) NOT NULL
,num_sales SMALLINT NOT NULL
,total_sales us_dollars NOT NULL
,master_cust_id INTEGER
,cust_insert_ts TIMESTAMP NOT NULL
,cust_update_ts TIMESTAMP NOT NULL
,PRIMARY KEY (cust_id)
,CONSTRAINT c1 CHECK (cust_name <> '')
,CONSTRAINT c2 CHECK (cust_sex = 'F'
OR cust_sex = 'M')
,CONSTRAINT c3 FOREIGN KEY (master_cust_id)
REFERENCES customer_balance (cust_id)
ON DELETE CASCADE);
Figure 908, Customer-Balance table DDL
CREATE TABLE us_sales
(invoice# INTEGER NOT NULL
,cust_id INTEGER NOT NULL
,sale_value us_dollars NOT NULL
,sale_insert_ts TIMESTAMP NOT NULL
,sale_update_ts TIMESTAMP NOT NULL
GENERATED ALWAYS
FOR EACH ROW ON UPDATE
AS ROW CHANGE TIMESTAMP
,PRIMARY KEY (invoice#)
,CONSTRAINT u1 CHECK (sale_value > us_dollars(0))
,CONSTRAINT u2 FOREIGN KEY (cust_id)
REFERENCES customer_balance
ON DELETE RESTRICT);
COMMIT;
CREATE INDEX us_sales_cust ON us_sales (cust_id);
Figure 909, US-Sales table DDL
SELECT *
FROM us_sales
WHERE sale_update_ts <= CURRENT TIMESTAMP;
Figure 910, Select run after multi-row insert
SELECT ROW CHANGE TIMESTAMP FOR us_sales
FROM us_sales
WHERE invoice# = 5;
Figure 911, Row change timestamp usage
UPDATE us_sales
SET sale_value = DECIMAL(sale_value) + 1
WHERE invoice# = 5
AND ROW CHANGE TIMESTAMP for us_sales = '2007-11-10-01.02.03';
Figure 912, Update that checks for intervening updates
CREATE TRIGGER cust_balance_ins1
NO CASCADE BEFORE INSERT
ON customer_balance
REFERENCING NEW AS nnn
FOR EACH ROW
MODE DB2SQL
SET nnn.num_sales = 0
,nnn.total_sales = 0
,nnn.cust_insert_ts = CURRENT TIMESTAMP
,nnn.cust_update_ts = CURRENT TIMESTAMP;
Figure 913, Set values during insert
CREATE TRIGGER cust_balance_upd1
NO CASCADE BEFORE UPDATE OF cust_update_ts
ON customer_balance
REFERENCING NEW AS nnn
FOR EACH ROW
MODE DB2SQL
SET nnn.cust_update_ts = CURRENT TIMESTAMP;
Figure 914, Set update-timestamp during update
CREATE TRIGGER cust_balance_upd2
NO CASCADE BEFORE UPDATE OF cust_insert_ts
ON customer_balance
FOR EACH ROW
MODE DB2SQL
SIGNAL SQLSTATE VALUE '71001'
SET MESSAGE_TEXT = 'Cannot update CUST insert-ts';
Figure 915, Prevent update of insert-timestamp
CREATE TRIGGER cust_balance_upd3
NO CASCADE BEFORE UPDATE OF num_sales, total_sales
ON customer_balance
REFERENCING NEW AS nnn
FOR EACH ROW
MODE DB2SQL
WHEN (CURRENT TIMESTAMP >
(SELECT MAX(sss.sale_update_ts)
FROM us_sales sss
WHERE nnn.cust_id = sss.cust_id))
SIGNAL SQLSTATE VALUE '71001'
SET MESSAGE_TEXT = 'Feilds only updated via US-Sales';
Figure 916, Prevent update of sales fields
CREATE SEQUENCE us_sales_seq
AS INTEGER
START WITH 1
INCREMENT BY 1
NO CYCLE
NO CACHE
ORDER;
Figure 917, Define sequence
CREATE TRIGGER us_sales_ins1
NO CASCADE BEFORE INSERT
ON us_sales
REFERENCING NEW AS nnn
FOR EACH ROW
MODE DB2SQL
SET nnn.invoice# = NEXTVAL FOR us_sales_seq
,nnn.sale_insert_ts = CURRENT TIMESTAMP;
Figure 918, Insert trigger
CREATE TRIGGER sales_to_cust_ins1
AFTER INSERT
ON us_sales
REFERENCING NEW AS nnn
FOR EACH ROW
MODE DB2SQL
UPDATE customer_balance ccc
SET ccc.num_sales = ccc.num_sales + 1
,ccc.total_sales = DECIMAL(ccc.total_sales) +
DECIMAL(nnn.sale_value)
WHERE ccc.cust_id = nnn.cust_id;
Figure 919, Propagate change to Customer-Balance table
CREATE TRIGGER us_sales_upd2
NO CASCADE BEFORE UPDATE OF cust_id, sale_insert_ts
ON us_sales
FOR EACH ROW
MODE DB2SQL
SIGNAL SQLSTATE VALUE '71001'
SET MESSAGE_TEXT = 'Can only update sale_value';
Figure 920, Prevent updates to selected columns
CREATE TRIGGER sales_to_cust_upd1
AFTER UPDATE OF sale_value
ON us_sales
REFERENCING NEW AS nnn
OLD AS ooo
FOR EACH ROW
MODE DB2SQL
UPDATE customer_balance ccc
SET ccc.total_sales = DECIMAL(ccc.total_sales) -
DECIMAL(ooo.sale_value) +
DECIMAL(nnn.sale_value)
WHERE ccc.cust_id = nnn.cust_id;
Figure 921, Propagate change to Customer-Balance table
CREATE TABLE customer
(cust# INTEGER NOT NULL
,cust_name CHAR(10)
,cust_mgr CHAR(10)
,PRIMARY KEY(cust#));
Figure 922, Customer table
CREATE TABLE customer_his
(cust# INTEGER NOT NULL
,cust_name CHAR(10)
,cust_mgr CHAR(10)
,cur_ts TIMESTAMP NOT NULL
,cur_actn CHAR(1) NOT NULL
,cur_user VARCHAR(10) NOT NULL
,prv_cust# INTEGER
,prv_ts TIMESTAMP
,PRIMARY KEY(cust#,cur_ts));
CREATE UNIQUE INDEX customer_his_x1 ON customer_his
(cust#, prv_ts, cur_ts);
Figure 923, Customer-history table
CREATE TRIGGER customer_ins
AFTER
INSERT ON customer
REFERENCING NEW AS nnn
FOR EACH ROW
MODE DB2SQL
INSERT INTO customer_his VALUES
(nnn.cust#
,nnn.cust_name
,nnn.cust_mgr
,CURRENT TIMESTAMP
,'I'
,USER
,NULL
,NULL);
Figure 924, Insert trigger
CREATE TRIGGER customer_upd
AFTER
UPDATE ON customer
REFERENCING NEW AS nnn
OLD AS ooo
FOR EACH ROW
MODE DB2SQL
INSERT INTO customer_his VALUES
(nnn.cust#
,nnn.cust_name
,nnn.cust_mgr
,CURRENT TIMESTAMP
,'U'
,USER
,ooo.cust#
,(SELECT MAX(cur_ts)
FROM customer_his hhh
WHERE ooo.cust# = hhh.cust#));
Figure 925, Update trigger
CREATE TRIGGER customer_del
AFTER
DELETE ON customer
REFERENCING OLD AS ooo
FOR EACH ROW
MODE DB2SQL
INSERT INTO customer_his VALUES
(ooo.cust#
,NULL
,NULL
,CURRENT TIMESTAMP
,'D'
,USER
,ooo.cust#
,(SELECT MAX(cur_ts)
FROM customer_his hhh
WHERE ooo.cust# = hhh.cust#));
Figure 926, Delete trigger
CREATE TABLE profile
(user_id VARCHAR(10) NOT NULL
,bgn_ts TIMESTAMP NOT NULL DEFAULT '9999-12-31-24.00.00'
,PRIMARY KEY(user_id));
Figure 927, Profile table
CREATE VIEW customer_vw AS
SELECT hhh.*
,ppp.bgn_ts
FROM customer_his hhh
,profile ppp
WHERE ppp.user_id = USER
AND hhh.cur_ts <= ppp.bgn_ts
AND hhh.cur_actn <> 'D'
AND NOT EXISTS
(SELECT *
FROM customer_his nnn
WHERE nnn.prv_cust# = hhh.cust#
AND nnn.prv_ts = hhh.cur_ts
AND nnn.cur_ts <= ppp.bgn_ts);
Figure 928, View of Customer history
CREATE TABLE version
(vrsn INTEGER NOT NULL
,vrsn_bgn_ts TIMESTAMP NOT NULL
,CONSTRAINT version1 CHECK(vrsn >= 0)
,CONSTRAINT version2 CHECK(vrsn < 1000000000)
,PRIMARY KEY(vrsn));
Figure 929, Version table
CREATE TABLE profile
(user_id VARCHAR(10) NOT NULL
,vrsn INTEGER NOT NULL
,vrsn_bgn_ts TIMESTAMP NOT NULL
,CONSTRAINT profile1 FOREIGN KEY(vrsn)
REFERENCES version(vrsn)
ON DELETE RESTRICT
,PRIMARY KEY(user_id));
Figure 930, Profile table
CREATE TABLE customer_his
(cust# INTEGER NOT NULL
,cust_name CHAR(10) NOT NULL
,cust_mgr CHAR(10)
,cur_ts TIMESTAMP NOT NULL
,cur_vrsn INTEGER NOT NULL
,cur_actn CHAR(1) NOT NULL
,cur_user VARCHAR(10) NOT NULL
,prv_cust# INTEGER
,prv_ts TIMESTAMP
,prv_vrsn INTEGER
,CONSTRAINT customer1 FOREIGN KEY(cur_vrsn)
REFERENCES version(vrsn)
ON DELETE RESTRICT
,CONSTRAINT customer2 CHECK(cur_actn IN ('I','U','D'))
,PRIMARY KEY(cust#,cur_vrsn,cur_ts));
CREATE INDEX customer_x2 ON customer_his
(prv_cust#
,prv_ts
,prv_vrsn);
Figure 931, Customer table
CREATE VIEW customer_vw AS
SELECT *
FROM customer_his hhh
,profile ppp
WHERE ppp.user_id = USER
AND hhh.cur_actn <> 'D'
AND ((ppp.vrsn = 0
AND hhh.cur_vrsn = 0)
OR (ppp.vrsn > 0
AND hhh.cur_vrsn = 0
AND hhh.cur_ts < ppp.vrsn_bgn_ts)
OR (ppp.vrsn > 0
AND hhh.cur_vrsn = ppp.vrsn))
AND NOT EXISTS
(SELECT *
FROM customer_his nnn
WHERE nnn.prv_cust# = hhh.cust#
AND nnn.prv_ts = hhh.cur_ts
AND nnn.prv_vrsn = hhh.cur_vrsn
AND ((ppp.vrsn = 0
AND nnn.cur_vrsn = 0)
OR (ppp.vrsn > 0
AND nnn.cur_vrsn = 0
AND nnn.cur_ts < ppp.vrsn_bgn_ts)
OR (ppp.vrsn > 0
AND nnn.cur_vrsn = ppp.vrsn)));
Figure 932, Customer view - 1 of 2
CREATE VIEW customer AS
SELECT cust#
,cust_name
,cust_mgr
FROM customer_vw;
Figure 933, Customer view - 2 of 2
CREATE TRIGGER customer_ins
INSTEAD OF
INSERT ON customer_vw
REFERENCING NEW AS nnn
FOR EACH ROW
MODE DB2SQL
INSERT INTO customer_his VALUES
(nnn.cust#
,nnn.cust_name
,nnn.cust_mgr
,CURRENT TIMESTAMP
,(SELECT vrsn
FROM profile
WHERE user_id = USER)
,CASE
WHEN 0 < (SELECT COUNT(*)
FROM customer
WHERE cust# = nnn.cust#)
THEN RAISE_ERROR('71001','ERROR: Duplicate cust#')
ELSE 'I'
END
,USER
,NULL
,NULL
,NULL);
Figure 934, Insert trigger
CREATE TRIGGER customer_upd
INSTEAD OF
UPDATE ON customer_vw
REFERENCING NEW AS nnn
OLD AS ooo
FOR EACH ROW
MODE DB2SQL
INSERT INTO customer_his VALUES
(nnn.cust#
,nnn.cust_name
,nnn.cust_mgr
,CURRENT TIMESTAMP
,ooo.vrsn
,CASE
WHEN nnn.cust# <> ooo.cust#
THEN RAISE_ERROR('72001','ERROR: Cannot change cust#')
ELSE 'U'
END
,ooo.user_id
,ooo.cust#
,ooo.cur_ts
,ooo.cur_vrsn);
Figure 935, Update trigger
CREATE TRIGGER customer_del
INSTEAD OF
DELETE ON customer_vw
REFERENCING OLD AS ooo
FOR EACH ROW
MODE DB2SQL
INSERT INTO customer_his VALUES
(ooo.cust#
,ooo.cust_name
,ooo.cust_mgr
,CURRENT TIMESTAMP
,ooo.vrsn
,'D'
,ooo.user_id
,ooo.cust#
,ooo.cur_ts
,ooo.cur_vrsn);
Figure 936, Delete trigger
SELECT 'SELECT COUNT(*) FROM ' CONCAT
RTRIM(tabschema) CONCAT
'.' CONCAT
tabname CONCAT
';'
FROM syscat.tables
WHERE tabschema = 'SYSCAT'
AND tabname LIKE 'N%'
ORDER BY tabschema ANSWER
,tabname; =========================================
SELECT COUNT(*) FROM SYSCAT.NAMEMAPPINGS;
SELECT COUNT(*) FROM SYSCAT.NODEGROUPDEF;
SELECT COUNT(*) FROM SYSCAT.NODEGROUPS;
Figure 937, Generate SQL to count rows
EXPORT TO C:\FRED.TXT OF DEL
MODIFIED BY NOCHARDEL
SELECT 'SELECT COUNT(*) FROM ' CONCAT
RTRIM(tabschema) CONCAT
'.' CONCAT
tabname CONCAT
';'
FROM syscat.tables
WHERE tabschema = 'SYSCAT'
AND tabname LIKE 'N%'
ORDER BY tabschema
,tabname;
Figure 938, Export generated SQL statements
SELECT 'SELECT ''' CONCAT
tabname CONCAT
''', COUNT(*) FROM ' CONCAT
RTRIM(tabschema) CONCAT
'.' CONCAT
tabname CONCAT
';'
FROM syscat.tables
WHERE tabschema = 'SYSCAT'
AND tabname LIKE 'N%'
ORDER BY tabschema
,tabname;
ANSWER
==========================================================
SELECT 'NAMEMAPPINGS', COUNT(*) FROM SYSCAT.NAMEMAPPINGS;
SELECT 'NODEGROUPDEF', COUNT(*) FROM SYSCAT.NODEGROUPDEF;
SELECT 'NODEGROUPS', COUNT(*) FROM SYSCAT.NODEGROUPS;
Figure 939, Generate SQL to count rows
WITH temp1 (num) AS
(VALUES (1),(2),(3),(4))
SELECT CASE num
WHEN 1 THEN 'SELECT '''
|| tabname
|| ''' AS tname'
WHEN 2 THEN ' ,COUNT(*)'
|| ' AS #rows'
WHEN 3 THEN 'FROM '
|| RTRIM(tabschema)
|| '.' ANSWER
|| tabname ==============================
|| ';' SELECT 'NAMEMAPPINGS' AS tname
WHEN 4 THEN '' ,COUNT(*) AS #rows
END FROM SYSCAT.NAMEMAPPINGS;
FROM syscat.tables
,temp1 SELECT 'NODEGROUPDEF' AS tname
WHERE tabschema = 'SYSCAT' ,COUNT(*) AS #rows
AND tabname LIKE 'N%' FROM SYSCAT.NODEGROUPDEF;
ORDER BY tabschema
,tabname SELECT 'NODEGROUPS' AS tname
,num; ,COUNT(*) AS #rows
FROM SYSCAT.NODEGROUPS;
Figure 940, Generate SQL to count rows
WITH temp1 (num) AS
(VALUES (1),(2),(3),(4))
SELECT CASE num
WHEN 1 THEN 'SELECT SUM(C1)'
when 2 then 'FROM ('
WHEN 3 THEN ' SELECT COUNT(*) AS C1 FROM ' CONCAT
RTRIM(tabschema) CONCAT
'.' CONCAT
tabname CONCAT
CASE dd
WHEN 1 THEN ''
ELSE ' UNION ALL'
END
WHEN 4 THEN ') AS xxx;'
END
FROM (SELECT tab.*
,ROW_NUMBER() OVER(ORDER BY tabschema ASC
,tabname ASC) AS aa
,ROW_NUMBER() OVER(ORDER BY tabschema DESC
,tabname DESC) AS dd
FROM syscat.tables tab
WHERE tabschema = 'SYSCAT'
AND tabname LIKE 'N%'
)AS xxx
,temp1
WHERE (num <= 2 AND aa = 1)
OR (num = 3)
OR (num = 4 AND dd = 1)
ORDER BY tabschema ASC
,tabname ASC
,num ASC;
ANSWER
===========================================================
SELECT SUM(C1)
FROM (
SELECT COUNT(*) AS C1 FROM SYSCAT.NAMEMAPPINGS UNION ALL
SELECT COUNT(*) AS C1 FROM SYSCAT.NODEGROUPDEF UNION ALL
SELECT COUNT(*) AS C1 FROM SYSCAT.NODEGROUPS
) AS xxx;
Figure 941, Generate SQL to count rows (all tables)
SELECT empno
,lastname
,workdept
,salary
FROM employee
WHERE empno = '000250';
Figure 942, Sample query
SELECT all-columns
FROM all-relevant-tables
WHERE all-predicates-are-true
Figure 943, Sample pseudo-query
SELECT COUNT(*)
FROM all-relevant-tables
WHERE empno = '000250';
Figure 944, Sample pseudo-query
SELECT CHAR(tabname,15) AS tabname
,get_INTEGER(
' SELECT COUNT(*)' ||
' FROM ' || tabschema || '.' || tabname ||
' WHERE ' || colname || ' = ''000250'''
) AS num_rows
FROM syscat.columns
WHERE tabschema = USER ANSWER
AND colname = 'EMPNO' ====================
AND typename = 'CHARACTER' TABNAME NUM_ROWS
ORDER BY tabname; ----------- --------
EMP_PHOTO 0
VEMP 1
VEMPDPT1 1
VEMPPROJACT 9
VSTAFAC2 9
Figure 945, Count matching rows in all matching tables
SELECT all-columns
FROM all-relevant-tables
WHERE empno = '000250';
Figure 946, Sample pseudo-query
WITH temp1 AS
(SELECT tabname
,VARCHAR(
' SELECT *' ||
' FROM ' || tabschema || '.' || tabname ||
' WHERE ' || colname || ' = ''000250'''
) AS SQL_text
FROM syscat.columns
WHERE tabschema = USER
AND colname = 'EMPNO'
AND typename = 'CHARACTER'
)
SELECT CHAR(t1.tabname,10) AS tabname
,t2.row_number AS row#
,t2.col_num AS col#
,CHAR(t2.col_name,15) AS colname
,CHAR(t2.col_type,15) AS coltype
,CHAR(t2.col_value,20) AS colvalue
FROM temp1 t1
,TABLE(tab_transpose(sql_text)) AS t2
ORDER BY t1.tabname
,t2.row_number
,t2.col_num;
Figure 947, Select all matching columns/rows in all matching tables
TABNAME ROW# COL# COLNAME COLTYPE COLVALUE
---------- ----- ---- --------- -------- ----------
EMPLOYEE 1 1 EMPNO CHAR 000250
EMPLOYEE 1 2 FIRSTNME VARCHAR DANIEL
EMPLOYEE 1 3 MIDINIT CHAR S
EMPLOYEE 1 4 LASTNAME VARCHAR SMITH
EMPLOYEE 1 5 WORKDEPT CHAR D21
EMPLOYEE 1 6 PHONENO CHAR 0961
EMPLOYEE 1 7 HIREDATE DATE 1999-10-30
EMPLOYEE 1 8 JOB CHAR CLERK
EMPLOYEE 1 9 EDLEVEL SMALLINT 15
EMPLOYEE 1 10 SEX CHAR M
EMPLOYEE 1 11 BIRTHDATE DATE 1969-11-12
EMPLOYEE 1 12 SALARY DECIMAL 49180.00
EMPLOYEE 1 13 BONUS DECIMAL 400.00
EMPLOYEE 1 14 COMM DECIMAL 1534.00
EMPPROJACT 1 1 EMPNO CHAR 000250
EMPPROJACT 1 2 PROJNO CHAR AD3112
EMPPROJACT 1 3 ACTNO SMALLINT 60
EMPPROJACT 1 4 EMPTIME DECIMAL 1.00
EMPPROJACT 1 5 EMSTDATE DATE 2002-01-01
EMPPROJACT 1 6 EMENDATE DATE 2002-02-01
EMPPROJACT 2 1 EMPNO CHAR 000250
EMPPROJACT 2 2 PROJNO CHAR AD3112
EMPPROJACT 2 3 ACTNO SMALLINT 60
EMPPROJACT 2 4 EMPTIME DECIMAL 0.50
EMPPROJACT 2 5 EMSTDATE DATE 2002-02-01
EMPPROJACT 2 6 EMENDATE DATE 2002-03-15
Figure 948, Transpose query output
SELECT CHAR(tabschema,8) AS schema
,CHAR(tabname,20) AS tabname
,return_INTEGER
('SELECT COUNT(*) ' ||
'FROM ' || tabschema || '.' || tabname
)AS #rows
FROM syscat.tables
WHERE tabschema = 'SYSCAT' ANSWER
AND tabname LIKE 'RO%' ============================
ORDER BY tabschema SCHEMA TABNAME #ROWS
,tabname ------ --------------- -----
FOR FETCH ONLY SYSCAT ROUTINEAUTH 168
WITH UR; SYSCAT ROUTINEDEP 41
SYSCAT ROUTINEPARMS 2035
SYSCAT ROUTINES 314
Figure 949, List tables, and count rows in same
CREATE FUNCTION return_INTEGER (in_stmt VARCHAR(4000))
RETURNS INTEGER
LANGUAGE SQL
READS SQL DATA
NO EXTERNAL ACTION
BEGIN ATOMIC
DECLARE out_val INTEGER;
CALL return_INTEGER(in_stmt,out_val);
RETURN out_val;
END
Figure 950, return_INTEGER function
CREATE PROCEDURE return_INTEGER (IN in_stmt VARCHAR(4000)
,OUT out_val INTEGER)
LANGUAGE SQL
READS SQL DATA
NO EXTERNAL ACTION
BEGIN
DECLARE c1 CURSOR FOR s1;
PREPARE s1 FROM in_stmt;
OPEN c1;
FETCH c1 INTO out_val;
CLOSE c1;
RETURN;
END
Figure 951, return_INTEGER stored procedure
CREATE PROCEDURE return_DECIMAL (IN in_stmt VARCHAR(4000)
,OUT out_val DECIMAL(31,6))
LANGUAGE SQL
READS SQL DATA
NO EXTERNAL ACTION
BEGIN
DECLARE c1 CURSOR FOR s1;
PREPARE s1 FROM in_stmt;
OPEN c1;
FETCH c1 INTO out_val;
CLOSE c1;
RETURN;
END
Figure 952, return_DECIMAL function
CREATE FUNCTION return_DECIMAL (in_stmt VARCHAR(4000))
RETURNS DECIMAL(31,6)
LANGUAGE SQL
READS SQL DATA
NO EXTERNAL ACTION
BEGIN ATOMIC
DECLARE out_val DECIMAL(31,6);
CALL return_DECIMAL(in_stmt,out_val);
RETURN out_val;
END
Figure 953, return_DECIMAL stored procedure
SELECT CHAR(tabschema,8) AS schema
,CHAR(tabname,20) AS tabname
,#rows
FROM (SELECT tabschema
,tabname
,return_INTEGER(
' SELECT COUNT(*)' ||
' FROM ' || tabschema || '.' || tabname ||
' FOR FETCH ONLY WITH UR'
) AS #rows
FROM syscat.tables tab
WHERE tabschema LIKE 'SYS%'
AND type = 'T'
AND stats_time IS NULL
)AS xxx
WHERE #rows > 1000 ANSWER
ORDER BY #rows DESC ============================
FOR FETCH ONLY SCHEMA TABNAME #ROWS
WITH UR; ------ --------------- -----
SYSIBM SYSCOLUMNS 3518
SYSIBM SYSROUTINEPARMS 2035
Figure 954, List tables never had RUNSTATS
SELECT CHAR(tab.tabname,15) AS tabname
,CHAR(col.colname,10) AS colname
,CHAR(COALESCE(return_VARCHAR(
' SELECT ''Y''' ||
' FROM ' || tab.tabschema || '.' || tab.tabname ||
' WHERE ' || col.colname || ' = ''A00''' ||
' FETCH FIRST 1 ROWS ONLY ' ||
' OPTIMIZE FOR 1 ROW ' ||
' WITH UR'
),'N'),1) AS has_dept
FROM syscat.columns col
,syscat.tables tab
WHERE col.tabschema = USER
AND col.colname IN ('DEPTNO','WORKDEPT')
AND col.tabschema = tab.tabschema
AND col.tabname = tab.tabname
AND tab.type = 'T'
FOR FETCH ONLY
WITH UR; ANSWER
=============================
TABNAME COLNAME HAS_DEPT
---------- --------- --------
DEPARTMENT DEPTNO Y
EMPLOYEE WORKDEPT Y
PROJECT DEPTNO N
Figure 955, List tables with a row for A00 department
SELECT CHAR(tab.tabname,15) AS tabname
,CHAR(col.colname,10) AS colname
,CHAR(COALESCE(return_VARCHAR(
' SELECT ''Y''' ||
' FROM ' || tab.tabschema || '.' || tab.tabname ||
' WHERE ' || col.colname || ' = ''A00''' ||
' FETCH FIRST 1 ROWS ONLY ' ||
' OPTIMIZE FOR 1 ROW ' ||
' WITH UR'
),'N'),1) AS has_dept
FROM syscat.columns col
,syscat.tables tab
WHERE col.tabschema = USER
AND col.colname IN ('DEPTNO','WORKDEPT')
AND col.tabschema = tab.tabschema
AND col.tabname = tab.tabname
AND tab.type = 'T'
AND col.colname IN
(SELECT SUBSTR(idx.colnames,2,LENGTH(col.colname))
FROM syscat.indexes idx
WHERE tab.tabschema = idx.tabschema
AND tab.tabname = idx.tabname)
FOR FETCH ONLY
WITH UR; ANSWER
===========================
TABNAME COLNAME HAS_DEPT
---------- ------- --------
DEPARTMENT DEPTNO Y
Figure 956, List suitably-indexed tables with a row for A00 department
CREATE FUNCTION get_Integer(VARCHAR(4000))
RETURNS INTEGER
LANGUAGE JAVA
EXTERNAL NAME 'Graeme2!get_Integer'
PARAMETER STYLE DB2GENERAL
NO EXTERNAL ACTION
NOT DETERMINISTIC
READS SQL DATA
FENCED;
Figure 957, CREATE FUNCTION code
import java.lang.*;
import COM.ibm.db2.app.*;
import java.sql.*;
import java.math.*;
import java.io.*;
public class Graeme2 extends UDF {
public void get_Integer(String inStmt,
int outValue)
throws Exception {
try {
Connection con = DriverManager.getConnection
("jdbc:default:connection");
PreparedStatement stmt = con.prepareStatement(inStmt);
ResultSet rs = stmt.executeQuery();
if (rs.next() == true && rs.getString(1) != null) {
set(2, rs.getInt(1));
}
rs.close();
stmt.close();
con.close();
}
catch (SQLException sqle) {
setSQLstate("38999");
setSQLmessage("SQLCODE = " + sqle.getSQLState());
return;
}
}
}
Figure 958, CREATE FUNCTION java code
ANSWER
==========================
DEPT EMPNO SALARY #ROWS
SELECT workdept AS dept ---- ------ -------- -----
,empno E11 000290 35340.00 7
,salary E21 200330 35370.00 6
,get_Integer( E21 200340 31840.00 6
' SELECT count(*)' ||
' FROM employee' ||
' where workdept = ''' || workdept || ''' ')
AS #rows
FROM employee
WHERE salary < 35500
ORDER BY workdept
,empno;
Figure 959, Java function usage example
CREATE FUNCTION tab_Varchar (VARCHAR(4000))
RETURNS TABLE (row_number INTEGER
,row_value VARCHAR(254))
LANGUAGE JAVA
EXTERNAL NAME 'Graeme2!tab_Varchar'
PARAMETER STYLE DB2GENERAL
NO EXTERNAL ACTION
NOT DETERMINISTIC
DISALLOW PARALLEL
READS SQL DATA
FINAL CALL
FENCED;
Figure 960, CREATE FUNCTION code
import java.lang.*;
import COM.ibm.db2.app.*;
import java.sql.*;
import java.math.*;
import java.io.*;
public class Graeme2 extends UDF {
Connection con;
Statement stmt;
ResultSet rs;
int rowNum;
public void tab_Varchar(String inStmt,
int outNumber,
String outValue)
throws Exception {
switch (getCallType()) {
case SQLUDF_TF_FIRST:
break;
case SQLUDF_TF_OPEN:
rowNum = 1;
try {
con = DriverManager.getConnection
("jdbc:default:connection");
stmt = con.createStatement();
rs = stmt.executeQuery(inStmt);
}
catch(SQLException sqle) {
setSQLstate("38999");
setSQLmessage("SQLCODE = " + sqle.getSQLState());
return;
}
break;
case SQLUDF_TF_FETCH:
if (rs.next() == true) {
set(2, rowNum);
if (rs.getString(1) != null) {
set(3, rs.getString(1));
}
rowNum++;
}
else {
setSQLstate ("02000");
}
break;
case SQLUDF_TF_CLOSE:
rs.close();
stmt.close();
con.close();
break;
case SQLUDF_TF_FINAL:
break;
}
}
}
Figure 961, CREATE FUNCTION java code
WITH
make_queries AS
(SELECT tab.tabschema
,tab.tabname
,' SELECT EMPNO ' ||
' FROM ' || tab.tabschema || '.' || tab.tabname
AS sql_text
FROM syscat.tables tab
,syscat.columns col
WHERE tab.tabschema = USER
AND tab.type = 'T'
AND col.tabschema = tab.tabschema
AND col.tabname = tab.tabname
AND col.colname = 'EMPNO'
AND col.typename = 'CHARACTER'
AND col.length = 6
),
run_queries AS
(SELECT qqq.*
,ttt.*
FROM make_queries qqq
,TABLE(tab_Varchar(sql_text)) AS ttt
)
SELECT CHAR(row_value,10) AS empno
,COUNT(*) AS #rows
,COUNT(DISTINCT tabschema || tabname) AS #tabs
,CHAR(MIN(tabname),18) AS min_tab
,CHAR(MAX(tabname),18) AS max_tab
FROM run_queries
GROUP BY row_value
HAVING COUNT(DISTINCT tabschema || tabname) > 3
ORDER BY row_value
FOR FETCH ONLY
WITH UR; ANSWER
======================================
EMPNO #ROWS#TABS MIN_TAB MAX_TAB
------ ---- ----- --------- ----------
000130 7 4 EMP_PHOTO EMPPROJACT
000140 10 4 EMP_PHOTO EMPPROJACT
000150 7 4 EMP_PHOTO EMPPROJACT
000190 7 4 EMP_PHOTO EMPPROJACT
Figure 962, Use Tabular Function
SELECT all columns
FROM unknown tables
WHERE any unknown columns = '%ABC%'
Figure 963, Cool query pseudo-code
SELECT *
FROM empprojact
WHERE empno = '000150';
ANSWER
=================================================
EMPNO PROJNO ACTNO EMPTIME EMSTDATE EMENDATE
------ ------ ----- ------- ---------- ----------
000150 MA2112 60 1.00 01/01/2002 07/15/2002
000150 MA2112 180 1.00 07/15/2002 02/01/2003
Figure 964, Select rows
SELECT SMALLINT(row_number) AS row#
,col_num AS col#
,CHAR(col_name,13) AS col_name
,CHAR(col_type,10) AS col_type
,col_length AS col_len
,SMALLINT(LENGTH(col_value)) AS val_len
,SUBSTR(col_value,1,20) AS col_value
FROM TABLE(tab_Transpose(
' SELECT *' ||
' FROM empprojact' ||
' WHERE empno = ''000150'''
)) AS ttt
ORDER BY 1,2; ANSWER
======================================================
ROW# COL# COL_NAME COL_TYPE COL_LEN VAL_LEN COL_VALUE
---- ---- -------- -------- ------- ------- ----------
1 1 EMPNO CHAR 6 6 000150
1 2 PROJNO CHAR 6 6 MA2112
1 3 ACTNO SMALLINT 6 2 60
1 4 EMPTIME DECIMAL 7 4 1.00
1 5 EMSTDATE DATE 10 10 2002-01-01
1 6 EMENDATE DATE 10 10 2002-07-15
2 1 EMPNO CHAR 6 6 000150
2 2 PROJNO CHAR 6 6 MA2112
2 3 ACTNO SMALLINT