375 lines
12 KiB
Plaintext
375 lines
12 KiB
Plaintext
--
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-- CONSTRAINTS
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-- Constraints can be specified with:
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-- - DEFAULT clause
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-- - CHECK clauses
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-- - PRIMARY KEY clauses
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-- - UNIQUE clauses
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--
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--
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-- DEFAULT syntax
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--
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CREATE TABLE DEFAULT_TBL (i int DEFAULT 100,
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x text DEFAULT 'vadim', f float8 DEFAULT 123.456);
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INSERT INTO DEFAULT_TBL VALUES (1, 'thomas', 57.0613);
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INSERT INTO DEFAULT_TBL VALUES (1, 'bruce');
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INSERT INTO DEFAULT_TBL (i, f) VALUES (2, 987.654);
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INSERT INTO DEFAULT_TBL (x) VALUES ('marc');
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INSERT INTO DEFAULT_TBL VALUES (3, null, 1.0);
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SELECT '' AS five, * FROM DEFAULT_TBL;
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five | i | x | f
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------+-----+--------+---------
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| 1 | thomas | 57.0613
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| 1 | bruce | 123.456
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| 2 | vadim | 987.654
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| 100 | marc | 123.456
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| 3 | | 1
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(5 rows)
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CREATE SEQUENCE DEFAULT_SEQ;
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CREATE TABLE DEFAULTEXPR_TBL (i1 int DEFAULT 100 + (200-199) * 2,
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i2 int DEFAULT nextval('default_seq'));
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INSERT INTO DEFAULTEXPR_TBL VALUES (-1, -2);
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INSERT INTO DEFAULTEXPR_TBL (i1) VALUES (-3);
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INSERT INTO DEFAULTEXPR_TBL (i2) VALUES (-4);
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INSERT INTO DEFAULTEXPR_TBL (i2) VALUES (NULL);
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SELECT '' AS four, * FROM DEFAULTEXPR_TBL;
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four | i1 | i2
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------+-----+----
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| -1 | -2
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| -3 | 1
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| 102 | -4
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| 102 |
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(4 rows)
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-- syntax errors
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-- test for extraneous comma
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CREATE TABLE error_tbl (i int DEFAULT (100, ));
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ERROR: syntax error at or near "," at character 43
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-- this will fail because gram.y uses b_expr not a_expr for defaults,
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-- to avoid a shift/reduce conflict that arises from NOT NULL being
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-- part of the column definition syntax:
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CREATE TABLE error_tbl (b1 bool DEFAULT 1 IN (1, 2));
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ERROR: syntax error at or near "IN" at character 43
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-- this should work, however:
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CREATE TABLE error_tbl (b1 bool DEFAULT (1 IN (1, 2)));
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DROP TABLE error_tbl;
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--
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-- CHECK syntax
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--
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CREATE TABLE CHECK_TBL (x int,
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CONSTRAINT CHECK_CON CHECK (x > 3));
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INSERT INTO CHECK_TBL VALUES (5);
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INSERT INTO CHECK_TBL VALUES (4);
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INSERT INTO CHECK_TBL VALUES (3);
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ERROR: new row for relation "check_tbl" violates check constraint "check_con"
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INSERT INTO CHECK_TBL VALUES (2);
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ERROR: new row for relation "check_tbl" violates check constraint "check_con"
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INSERT INTO CHECK_TBL VALUES (6);
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INSERT INTO CHECK_TBL VALUES (1);
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ERROR: new row for relation "check_tbl" violates check constraint "check_con"
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SELECT '' AS three, * FROM CHECK_TBL;
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three | x
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-------+---
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| 5
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| 4
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| 6
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(3 rows)
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CREATE SEQUENCE CHECK_SEQ;
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CREATE TABLE CHECK2_TBL (x int, y text, z int,
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CONSTRAINT SEQUENCE_CON
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CHECK (x > 3 and y <> 'check failed' and z < 8));
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INSERT INTO CHECK2_TBL VALUES (4, 'check ok', -2);
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INSERT INTO CHECK2_TBL VALUES (1, 'x check failed', -2);
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ERROR: new row for relation "check2_tbl" violates check constraint "sequence_con"
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INSERT INTO CHECK2_TBL VALUES (5, 'z check failed', 10);
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ERROR: new row for relation "check2_tbl" violates check constraint "sequence_con"
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INSERT INTO CHECK2_TBL VALUES (0, 'check failed', -2);
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ERROR: new row for relation "check2_tbl" violates check constraint "sequence_con"
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INSERT INTO CHECK2_TBL VALUES (6, 'check failed', 11);
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ERROR: new row for relation "check2_tbl" violates check constraint "sequence_con"
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INSERT INTO CHECK2_TBL VALUES (7, 'check ok', 7);
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SELECT '' AS two, * from CHECK2_TBL;
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two | x | y | z
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-----+---+----------+----
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| 4 | check ok | -2
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| 7 | check ok | 7
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(2 rows)
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--
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-- Check constraints on INSERT
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--
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CREATE SEQUENCE INSERT_SEQ;
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CREATE TABLE INSERT_TBL (x INT DEFAULT nextval('insert_seq'),
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y TEXT DEFAULT '-NULL-',
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z INT DEFAULT -1 * currval('insert_seq'),
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CONSTRAINT INSERT_CON CHECK (x >= 3 AND y <> 'check failed' AND x < 8),
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CHECK (x + z = 0));
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INSERT INTO INSERT_TBL(x,z) VALUES (2, -2);
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ERROR: new row for relation "insert_tbl" violates check constraint "insert_con"
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SELECT '' AS zero, * FROM INSERT_TBL;
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zero | x | y | z
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------+---+---+---
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(0 rows)
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SELECT 'one' AS one, nextval('insert_seq');
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one | nextval
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-----+---------
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one | 1
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(1 row)
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INSERT INTO INSERT_TBL(y) VALUES ('Y');
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ERROR: new row for relation "insert_tbl" violates check constraint "insert_con"
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INSERT INTO INSERT_TBL(y) VALUES ('Y');
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INSERT INTO INSERT_TBL(x,z) VALUES (1, -2);
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ERROR: new row for relation "insert_tbl" violates check constraint "$1"
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INSERT INTO INSERT_TBL(z,x) VALUES (-7, 7);
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INSERT INTO INSERT_TBL VALUES (5, 'check failed', -5);
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ERROR: new row for relation "insert_tbl" violates check constraint "insert_con"
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INSERT INTO INSERT_TBL VALUES (7, '!check failed', -7);
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INSERT INTO INSERT_TBL(y) VALUES ('-!NULL-');
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SELECT '' AS four, * FROM INSERT_TBL;
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four | x | y | z
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------+---+---------------+----
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| 3 | Y | -3
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| 7 | -NULL- | -7
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| 7 | !check failed | -7
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| 4 | -!NULL- | -4
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(4 rows)
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INSERT INTO INSERT_TBL(y,z) VALUES ('check failed', 4);
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ERROR: new row for relation "insert_tbl" violates check constraint "$1"
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INSERT INTO INSERT_TBL(x,y) VALUES (5, 'check failed');
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ERROR: new row for relation "insert_tbl" violates check constraint "insert_con"
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INSERT INTO INSERT_TBL(x,y) VALUES (5, '!check failed');
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INSERT INTO INSERT_TBL(y) VALUES ('-!NULL-');
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SELECT '' AS six, * FROM INSERT_TBL;
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six | x | y | z
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-----+---+---------------+----
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| 3 | Y | -3
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| 7 | -NULL- | -7
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| 7 | !check failed | -7
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| 4 | -!NULL- | -4
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| 5 | !check failed | -5
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| 6 | -!NULL- | -6
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(6 rows)
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SELECT 'seven' AS one, nextval('insert_seq');
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one | nextval
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-------+---------
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seven | 7
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(1 row)
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INSERT INTO INSERT_TBL(y) VALUES ('Y');
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ERROR: new row for relation "insert_tbl" violates check constraint "insert_con"
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SELECT 'eight' AS one, currval('insert_seq');
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one | currval
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-------+---------
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eight | 8
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(1 row)
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-- According to SQL92, it is OK to insert a record that gives rise to NULL
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-- constraint-condition results. Postgres used to reject this, but it
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-- was wrong:
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INSERT INTO INSERT_TBL VALUES (null, null, null);
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SELECT '' AS nine, * FROM INSERT_TBL;
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nine | x | y | z
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------+---+---------------+----
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| 3 | Y | -3
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| 7 | -NULL- | -7
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| 7 | !check failed | -7
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| 4 | -!NULL- | -4
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| 5 | !check failed | -5
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| 6 | -!NULL- | -6
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| | |
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(7 rows)
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--
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-- Check inheritance of defaults and constraints
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--
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CREATE TABLE INSERT_CHILD (cx INT default 42,
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cy INT CHECK (cy > x))
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INHERITS (INSERT_TBL);
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INSERT INTO INSERT_CHILD(x,z,cy) VALUES (7,-7,11);
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INSERT INTO INSERT_CHILD(x,z,cy) VALUES (7,-7,6);
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ERROR: new row for relation "insert_child" violates check constraint "insert_child_cy"
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INSERT INTO INSERT_CHILD(x,z,cy) VALUES (6,-7,7);
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ERROR: new row for relation "insert_child" violates check constraint "$1"
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INSERT INTO INSERT_CHILD(x,y,z,cy) VALUES (6,'check failed',-6,7);
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ERROR: new row for relation "insert_child" violates check constraint "insert_con"
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SELECT * FROM INSERT_CHILD;
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x | y | z | cx | cy
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---+--------+----+----+----
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7 | -NULL- | -7 | 42 | 11
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(1 row)
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DROP TABLE INSERT_CHILD;
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--
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-- Check constraints on INSERT INTO
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--
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DELETE FROM INSERT_TBL;
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DROP SEQUENCE INSERT_SEQ;
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CREATE SEQUENCE INSERT_SEQ START 4;
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CREATE TABLE tmp (xd INT, yd TEXT, zd INT);
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INSERT INTO tmp VALUES (null, 'Y', null);
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INSERT INTO tmp VALUES (5, '!check failed', null);
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INSERT INTO tmp VALUES (null, 'try again', null);
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INSERT INTO INSERT_TBL(y) select yd from tmp;
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SELECT '' AS three, * FROM INSERT_TBL;
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three | x | y | z
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-------+---+---------------+----
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| 4 | Y | -4
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| 5 | !check failed | -5
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| 6 | try again | -6
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(3 rows)
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INSERT INTO INSERT_TBL SELECT * FROM tmp WHERE yd = 'try again';
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INSERT INTO INSERT_TBL(y,z) SELECT yd, -7 FROM tmp WHERE yd = 'try again';
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INSERT INTO INSERT_TBL(y,z) SELECT yd, -8 FROM tmp WHERE yd = 'try again';
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ERROR: new row for relation "insert_tbl" violates check constraint "insert_con"
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SELECT '' AS four, * FROM INSERT_TBL;
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four | x | y | z
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------+---+---------------+----
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| 4 | Y | -4
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| 5 | !check failed | -5
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| 6 | try again | -6
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| | try again |
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| 7 | try again | -7
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(5 rows)
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DROP TABLE tmp;
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--
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-- Check constraints on UPDATE
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--
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UPDATE INSERT_TBL SET x = NULL WHERE x = 5;
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UPDATE INSERT_TBL SET x = 6 WHERE x = 6;
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UPDATE INSERT_TBL SET x = -z, z = -x;
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UPDATE INSERT_TBL SET x = z, z = x;
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ERROR: new row for relation "insert_tbl" violates check constraint "insert_con"
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SELECT * FROM INSERT_TBL;
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x | y | z
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---+---------------+----
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4 | Y | -4
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| try again |
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7 | try again | -7
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5 | !check failed |
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6 | try again | -6
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(5 rows)
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-- DROP TABLE INSERT_TBL;
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--
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-- Check constraints on COPY FROM
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--
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CREATE TABLE COPY_TBL (x INT, y TEXT, z INT,
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CONSTRAINT COPY_CON
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CHECK (x > 3 AND y <> 'check failed' AND x < 7 ));
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COPY COPY_TBL FROM '@abs_srcdir@/data/constro.data';
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SELECT '' AS two, * FROM COPY_TBL;
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two | x | y | z
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-----+---+---------------+---
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| 4 | !check failed | 5
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| 6 | OK | 4
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(2 rows)
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COPY COPY_TBL FROM '@abs_srcdir@/data/constrf.data';
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ERROR: new row for relation "copy_tbl" violates check constraint "copy_con"
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CONTEXT: COPY copy_tbl, line 2: "7 check failed 6"
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SELECT * FROM COPY_TBL;
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x | y | z
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---+---------------+---
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4 | !check failed | 5
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6 | OK | 4
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(2 rows)
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--
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-- Primary keys
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--
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CREATE TABLE PRIMARY_TBL (i int PRIMARY KEY, t text);
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NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "primary_tbl_pkey" for table "primary_tbl"
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INSERT INTO PRIMARY_TBL VALUES (1, 'one');
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INSERT INTO PRIMARY_TBL VALUES (2, 'two');
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INSERT INTO PRIMARY_TBL VALUES (1, 'three');
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ERROR: duplicate key violates unique constraint "primary_tbl_pkey"
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INSERT INTO PRIMARY_TBL VALUES (4, 'three');
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INSERT INTO PRIMARY_TBL VALUES (5, 'one');
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INSERT INTO PRIMARY_TBL (t) VALUES ('six');
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ERROR: null value in column "i" violates not-null constraint
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SELECT '' AS four, * FROM PRIMARY_TBL;
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four | i | t
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------+---+-------
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| 1 | one
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| 2 | two
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| 4 | three
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| 5 | one
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(4 rows)
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DROP TABLE PRIMARY_TBL;
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CREATE TABLE PRIMARY_TBL (i int, t text,
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PRIMARY KEY(i,t));
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NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "primary_tbl_pkey" for table "primary_tbl"
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INSERT INTO PRIMARY_TBL VALUES (1, 'one');
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INSERT INTO PRIMARY_TBL VALUES (2, 'two');
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INSERT INTO PRIMARY_TBL VALUES (1, 'three');
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INSERT INTO PRIMARY_TBL VALUES (4, 'three');
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INSERT INTO PRIMARY_TBL VALUES (5, 'one');
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INSERT INTO PRIMARY_TBL (t) VALUES ('six');
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ERROR: null value in column "i" violates not-null constraint
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SELECT '' AS three, * FROM PRIMARY_TBL;
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three | i | t
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-------+---+-------
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| 1 | one
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| 2 | two
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| 1 | three
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| 4 | three
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| 5 | one
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(5 rows)
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DROP TABLE PRIMARY_TBL;
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--
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-- Unique keys
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--
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CREATE TABLE UNIQUE_TBL (i int UNIQUE, t text);
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NOTICE: CREATE TABLE / UNIQUE will create implicit index "unique_tbl_i_key" for table "unique_tbl"
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INSERT INTO UNIQUE_TBL VALUES (1, 'one');
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INSERT INTO UNIQUE_TBL VALUES (2, 'two');
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INSERT INTO UNIQUE_TBL VALUES (1, 'three');
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ERROR: duplicate key violates unique constraint "unique_tbl_i_key"
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INSERT INTO UNIQUE_TBL VALUES (4, 'four');
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INSERT INTO UNIQUE_TBL VALUES (5, 'one');
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INSERT INTO UNIQUE_TBL (t) VALUES ('six');
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INSERT INTO UNIQUE_TBL (t) VALUES ('seven');
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SELECT '' AS five, * FROM UNIQUE_TBL;
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five | i | t
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------+---+-------
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| 1 | one
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| 2 | two
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| 4 | four
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| 5 | one
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| | six
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| | seven
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(6 rows)
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DROP TABLE UNIQUE_TBL;
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CREATE TABLE UNIQUE_TBL (i int, t text,
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UNIQUE(i,t));
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NOTICE: CREATE TABLE / UNIQUE will create implicit index "unique_tbl_i_key" for table "unique_tbl"
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INSERT INTO UNIQUE_TBL VALUES (1, 'one');
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INSERT INTO UNIQUE_TBL VALUES (2, 'two');
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INSERT INTO UNIQUE_TBL VALUES (1, 'three');
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INSERT INTO UNIQUE_TBL VALUES (1, 'one');
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ERROR: duplicate key violates unique constraint "unique_tbl_i_key"
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INSERT INTO UNIQUE_TBL VALUES (5, 'one');
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INSERT INTO UNIQUE_TBL (t) VALUES ('six');
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SELECT '' AS five, * FROM UNIQUE_TBL;
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five | i | t
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------+---+-------
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| 1 | one
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| 2 | two
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| 1 | three
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| 5 | one
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| | six
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(5 rows)
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DROP TABLE UNIQUE_TBL;
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