-- -- CONSTRAINTS -- Constraints can be specified with: -- - DEFAULT clause -- - CHECK clauses -- - PRIMARY KEY clauses -- - UNIQUE clauses -- - EXCLUDE clauses -- -- -- DEFAULT syntax -- CREATE TABLE DEFAULT_TBL (i int DEFAULT 100, x text DEFAULT 'vadim', f float8 DEFAULT 123.456); INSERT INTO DEFAULT_TBL VALUES (1, 'thomas', 57.0613); INSERT INTO DEFAULT_TBL VALUES (1, 'bruce'); INSERT INTO DEFAULT_TBL (i, f) VALUES (2, 987.654); INSERT INTO DEFAULT_TBL (x) VALUES ('marc'); INSERT INTO DEFAULT_TBL VALUES (3, null, 1.0); SELECT '' AS five, * FROM DEFAULT_TBL; five | i | x | f ------+-----+--------+--------- | 1 | thomas | 57.0613 | 1 | bruce | 123.456 | 2 | vadim | 987.654 | 100 | marc | 123.456 | 3 | | 1 (5 rows) CREATE SEQUENCE DEFAULT_SEQ; CREATE TABLE DEFAULTEXPR_TBL (i1 int DEFAULT 100 + (200-199) * 2, i2 int DEFAULT nextval('default_seq')); INSERT INTO DEFAULTEXPR_TBL VALUES (-1, -2); INSERT INTO DEFAULTEXPR_TBL (i1) VALUES (-3); INSERT INTO DEFAULTEXPR_TBL (i2) VALUES (-4); INSERT INTO DEFAULTEXPR_TBL (i2) VALUES (NULL); SELECT '' AS four, * FROM DEFAULTEXPR_TBL; four | i1 | i2 ------+-----+---- | -1 | -2 | -3 | 1 | 102 | -4 | 102 | (4 rows) -- syntax errors -- test for extraneous comma CREATE TABLE error_tbl (i int DEFAULT (100, )); ERROR: syntax error at or near ")" LINE 1: CREATE TABLE error_tbl (i int DEFAULT (100, )); ^ -- this will fail because gram.y uses b_expr not a_expr for defaults, -- to avoid a shift/reduce conflict that arises from NOT NULL being -- part of the column definition syntax: CREATE TABLE error_tbl (b1 bool DEFAULT 1 IN (1, 2)); ERROR: syntax error at or near "IN" LINE 1: CREATE TABLE error_tbl (b1 bool DEFAULT 1 IN (1, 2)); ^ -- this should work, however: CREATE TABLE error_tbl (b1 bool DEFAULT (1 IN (1, 2))); DROP TABLE error_tbl; -- -- CHECK syntax -- CREATE TABLE CHECK_TBL (x int, CONSTRAINT CHECK_CON CHECK (x > 3)); INSERT INTO CHECK_TBL VALUES (5); INSERT INTO CHECK_TBL VALUES (4); INSERT INTO CHECK_TBL VALUES (3); ERROR: new row for relation "check_tbl" violates check constraint "check_con" DETAIL: Failing row contains (3). INSERT INTO CHECK_TBL VALUES (2); ERROR: new row for relation "check_tbl" violates check constraint "check_con" DETAIL: Failing row contains (2). INSERT INTO CHECK_TBL VALUES (6); INSERT INTO CHECK_TBL VALUES (1); ERROR: new row for relation "check_tbl" violates check constraint "check_con" DETAIL: Failing row contains (1). SELECT '' AS three, * FROM CHECK_TBL; three | x -------+--- | 5 | 4 | 6 (3 rows) CREATE SEQUENCE CHECK_SEQ; CREATE TABLE CHECK2_TBL (x int, y text, z int, CONSTRAINT SEQUENCE_CON CHECK (x > 3 and y <> 'check failed' and z < 8)); INSERT INTO CHECK2_TBL VALUES (4, 'check ok', -2); INSERT INTO CHECK2_TBL VALUES (1, 'x check failed', -2); ERROR: new row for relation "check2_tbl" violates check constraint "sequence_con" DETAIL: Failing row contains (1, x check failed, -2). INSERT INTO CHECK2_TBL VALUES (5, 'z check failed', 10); ERROR: new row for relation "check2_tbl" violates check constraint "sequence_con" DETAIL: Failing row contains (5, z check failed, 10). INSERT INTO CHECK2_TBL VALUES (0, 'check failed', -2); ERROR: new row for relation "check2_tbl" violates check constraint "sequence_con" DETAIL: Failing row contains (0, check failed, -2). INSERT INTO CHECK2_TBL VALUES (6, 'check failed', 11); ERROR: new row for relation "check2_tbl" violates check constraint "sequence_con" DETAIL: Failing row contains (6, check failed, 11). INSERT INTO CHECK2_TBL VALUES (7, 'check ok', 7); SELECT '' AS two, * from CHECK2_TBL; two | x | y | z -----+---+----------+---- | 4 | check ok | -2 | 7 | check ok | 7 (2 rows) -- -- Check constraints on INSERT -- CREATE SEQUENCE INSERT_SEQ; CREATE TABLE INSERT_TBL (x INT DEFAULT nextval('insert_seq'), y TEXT DEFAULT '-NULL-', z INT DEFAULT -1 * currval('insert_seq'), CONSTRAINT INSERT_TBL_CON CHECK (x >= 3 AND y <> 'check failed' AND x < 8), CHECK (x + z = 0)); INSERT INTO INSERT_TBL(x,z) VALUES (2, -2); ERROR: new row for relation "insert_tbl" violates check constraint "insert_tbl_con" DETAIL: Failing row contains (2, -NULL-, -2). SELECT '' AS zero, * FROM INSERT_TBL; zero | x | y | z ------+---+---+--- (0 rows) SELECT 'one' AS one, nextval('insert_seq'); one | nextval -----+--------- one | 1 (1 row) INSERT INTO INSERT_TBL(y) VALUES ('Y'); ERROR: new row for relation "insert_tbl" violates check constraint "insert_tbl_con" DETAIL: Failing row contains (2, Y, -2). INSERT INTO INSERT_TBL(y) VALUES ('Y'); INSERT INTO INSERT_TBL(x,z) VALUES (1, -2); ERROR: new row for relation "insert_tbl" violates check constraint "insert_tbl_check" DETAIL: Failing row contains (1, -NULL-, -2). INSERT INTO INSERT_TBL(z,x) VALUES (-7, 7); INSERT INTO INSERT_TBL VALUES (5, 'check failed', -5); ERROR: new row for relation "insert_tbl" violates check constraint "insert_tbl_con" DETAIL: Failing row contains (5, check failed, -5). INSERT INTO INSERT_TBL VALUES (7, '!check failed', -7); INSERT INTO INSERT_TBL(y) VALUES ('-!NULL-'); SELECT '' AS four, * FROM INSERT_TBL; four | x | y | z ------+---+---------------+---- | 3 | Y | -3 | 7 | -NULL- | -7 | 7 | !check failed | -7 | 4 | -!NULL- | -4 (4 rows) INSERT INTO INSERT_TBL(y,z) VALUES ('check failed', 4); ERROR: new row for relation "insert_tbl" violates check constraint "insert_tbl_check" DETAIL: Failing row contains (5, check failed, 4). INSERT INTO INSERT_TBL(x,y) VALUES (5, 'check failed'); ERROR: new row for relation "insert_tbl" violates check constraint "insert_tbl_con" DETAIL: Failing row contains (5, check failed, -5). INSERT INTO INSERT_TBL(x,y) VALUES (5, '!check failed'); INSERT INTO INSERT_TBL(y) VALUES ('-!NULL-'); SELECT '' AS six, * FROM INSERT_TBL; six | x | y | z -----+---+---------------+---- | 3 | Y | -3 | 7 | -NULL- | -7 | 7 | !check failed | -7 | 4 | -!NULL- | -4 | 5 | !check failed | -5 | 6 | -!NULL- | -6 (6 rows) SELECT 'seven' AS one, nextval('insert_seq'); one | nextval -------+--------- seven | 7 (1 row) INSERT INTO INSERT_TBL(y) VALUES ('Y'); ERROR: new row for relation "insert_tbl" violates check constraint "insert_tbl_con" DETAIL: Failing row contains (8, Y, -8). SELECT 'eight' AS one, currval('insert_seq'); one | currval -------+--------- eight | 8 (1 row) -- According to SQL, it is OK to insert a record that gives rise to NULL -- constraint-condition results. Postgres used to reject this, but it -- was wrong: INSERT INTO INSERT_TBL VALUES (null, null, null); SELECT '' AS nine, * FROM INSERT_TBL; nine | x | y | z ------+---+---------------+---- | 3 | Y | -3 | 7 | -NULL- | -7 | 7 | !check failed | -7 | 4 | -!NULL- | -4 | 5 | !check failed | -5 | 6 | -!NULL- | -6 | | | (7 rows) -- -- Check constraints on system columns -- CREATE TABLE SYS_COL_CHECK_TBL (city text, state text, is_capital bool, altitude int, CHECK (NOT (is_capital AND tableoid::regclass::text = 'sys_col_check_tbl'))); INSERT INTO SYS_COL_CHECK_TBL VALUES ('Seattle', 'Washington', false, 100); INSERT INTO SYS_COL_CHECK_TBL VALUES ('Olympia', 'Washington', true, 100); ERROR: new row for relation "sys_col_check_tbl" violates check constraint "sys_col_check_tbl_check" DETAIL: Failing row contains (Olympia, Washington, t, 100). SELECT *, tableoid::regclass::text FROM SYS_COL_CHECK_TBL; city | state | is_capital | altitude | tableoid ---------+------------+------------+----------+------------------- Seattle | Washington | f | 100 | sys_col_check_tbl (1 row) DROP TABLE SYS_COL_CHECK_TBL; -- -- Check constraints on system columns other then TableOid should return error -- CREATE TABLE SYS_COL_CHECK_TBL (city text, state text, is_capital bool, altitude int, CHECK (NOT (is_capital AND ctid::text = 'sys_col_check_tbl'))); ERROR: system column "ctid" reference in check constraint is invalid LINE 3: CHECK (NOT (is_capital AND ctid::text = 'sys_col_check... ^ -- -- Check inheritance of defaults and constraints -- CREATE TABLE INSERT_CHILD (cx INT default 42, cy INT CHECK (cy > x)) INHERITS (INSERT_TBL); INSERT INTO INSERT_CHILD(x,z,cy) VALUES (7,-7,11); INSERT INTO INSERT_CHILD(x,z,cy) VALUES (7,-7,6); ERROR: new row for relation "insert_child" violates check constraint "insert_child_check" DETAIL: Failing row contains (7, -NULL-, -7, 42, 6). INSERT INTO INSERT_CHILD(x,z,cy) VALUES (6,-7,7); ERROR: new row for relation "insert_child" violates check constraint "insert_tbl_check" DETAIL: Failing row contains (6, -NULL-, -7, 42, 7). INSERT INTO INSERT_CHILD(x,y,z,cy) VALUES (6,'check failed',-6,7); ERROR: new row for relation "insert_child" violates check constraint "insert_tbl_con" DETAIL: Failing row contains (6, check failed, -6, 42, 7). SELECT * FROM INSERT_CHILD; x | y | z | cx | cy ---+--------+----+----+---- 7 | -NULL- | -7 | 42 | 11 (1 row) DROP TABLE INSERT_CHILD; -- -- Check NO INHERIT type of constraints and inheritance -- CREATE TABLE ATACC1 (TEST INT CHECK (TEST > 0) NO INHERIT); CREATE TABLE ATACC2 (TEST2 INT) INHERITS (ATACC1); -- check constraint is not there on child INSERT INTO ATACC2 (TEST) VALUES (-3); -- check constraint is there on parent INSERT INTO ATACC1 (TEST) VALUES (-3); ERROR: new row for relation "atacc1" violates check constraint "atacc1_test_check" DETAIL: Failing row contains (-3). DROP TABLE ATACC1 CASCADE; NOTICE: drop cascades to table atacc2 CREATE TABLE ATACC1 (TEST INT, TEST2 INT CHECK (TEST > 0), CHECK (TEST2 > 10) NO INHERIT); CREATE TABLE ATACC2 () INHERITS (ATACC1); -- check constraint is there on child INSERT INTO ATACC2 (TEST) VALUES (-3); ERROR: new row for relation "atacc2" violates check constraint "atacc1_test_check" DETAIL: Failing row contains (-3, null). -- check constraint is there on parent INSERT INTO ATACC1 (TEST) VALUES (-3); ERROR: new row for relation "atacc1" violates check constraint "atacc1_test_check" DETAIL: Failing row contains (-3, null). -- check constraint is not there on child INSERT INTO ATACC2 (TEST2) VALUES (3); -- check constraint is there on parent INSERT INTO ATACC1 (TEST2) VALUES (3); ERROR: new row for relation "atacc1" violates check constraint "atacc1_test2_check" DETAIL: Failing row contains (null, 3). DROP TABLE ATACC1 CASCADE; NOTICE: drop cascades to table atacc2 -- -- Check constraints on INSERT INTO -- DELETE FROM INSERT_TBL; ALTER SEQUENCE INSERT_SEQ RESTART WITH 4; CREATE TABLE tmp (xd INT, yd TEXT, zd INT); INSERT INTO tmp VALUES (null, 'Y', null); INSERT INTO tmp VALUES (5, '!check failed', null); INSERT INTO tmp VALUES (null, 'try again', null); INSERT INTO INSERT_TBL(y) select yd from tmp; SELECT '' AS three, * FROM INSERT_TBL; three | x | y | z -------+---+---------------+---- | 4 | Y | -4 | 5 | !check failed | -5 | 6 | try again | -6 (3 rows) INSERT INTO INSERT_TBL SELECT * FROM tmp WHERE yd = 'try again'; INSERT INTO INSERT_TBL(y,z) SELECT yd, -7 FROM tmp WHERE yd = 'try again'; INSERT INTO INSERT_TBL(y,z) SELECT yd, -8 FROM tmp WHERE yd = 'try again'; ERROR: new row for relation "insert_tbl" violates check constraint "insert_tbl_con" DETAIL: Failing row contains (8, try again, -8). SELECT '' AS four, * FROM INSERT_TBL; four | x | y | z ------+---+---------------+---- | 4 | Y | -4 | 5 | !check failed | -5 | 6 | try again | -6 | | try again | | 7 | try again | -7 (5 rows) DROP TABLE tmp; -- -- Check constraints on UPDATE -- UPDATE INSERT_TBL SET x = NULL WHERE x = 5; UPDATE INSERT_TBL SET x = 6 WHERE x = 6; UPDATE INSERT_TBL SET x = -z, z = -x; UPDATE INSERT_TBL SET x = z, z = x; ERROR: new row for relation "insert_tbl" violates check constraint "insert_tbl_con" DETAIL: Failing row contains (-4, Y, 4). SELECT * FROM INSERT_TBL; x | y | z ---+---------------+---- 4 | Y | -4 | try again | 7 | try again | -7 5 | !check failed | 6 | try again | -6 (5 rows) -- DROP TABLE INSERT_TBL; -- -- Check constraints on COPY FROM -- CREATE TABLE COPY_TBL (x INT, y TEXT, z INT, CONSTRAINT COPY_CON CHECK (x > 3 AND y <> 'check failed' AND x < 7 )); COPY COPY_TBL FROM '@abs_srcdir@/data/constro.data'; SELECT '' AS two, * FROM COPY_TBL; two | x | y | z -----+---+---------------+--- | 4 | !check failed | 5 | 6 | OK | 4 (2 rows) COPY COPY_TBL FROM '@abs_srcdir@/data/constrf.data'; ERROR: new row for relation "copy_tbl" violates check constraint "copy_con" DETAIL: Failing row contains (7, check failed, 6). CONTEXT: COPY copy_tbl, line 2: "7 check failed 6" SELECT * FROM COPY_TBL; x | y | z ---+---------------+--- 4 | !check failed | 5 6 | OK | 4 (2 rows) -- -- Primary keys -- CREATE TABLE PRIMARY_TBL (i int PRIMARY KEY, t text); INSERT INTO PRIMARY_TBL VALUES (1, 'one'); INSERT INTO PRIMARY_TBL VALUES (2, 'two'); INSERT INTO PRIMARY_TBL VALUES (1, 'three'); ERROR: duplicate key value violates unique constraint "primary_tbl_pkey" DETAIL: Key (i)=(1) already exists. INSERT INTO PRIMARY_TBL VALUES (4, 'three'); INSERT INTO PRIMARY_TBL VALUES (5, 'one'); INSERT INTO PRIMARY_TBL (t) VALUES ('six'); ERROR: null value in column "i" violates not-null constraint DETAIL: Failing row contains (null, six). SELECT '' AS four, * FROM PRIMARY_TBL; four | i | t ------+---+------- | 1 | one | 2 | two | 4 | three | 5 | one (4 rows) DROP TABLE PRIMARY_TBL; CREATE TABLE PRIMARY_TBL (i int, t text, PRIMARY KEY(i,t)); INSERT INTO PRIMARY_TBL VALUES (1, 'one'); INSERT INTO PRIMARY_TBL VALUES (2, 'two'); INSERT INTO PRIMARY_TBL VALUES (1, 'three'); INSERT INTO PRIMARY_TBL VALUES (4, 'three'); INSERT INTO PRIMARY_TBL VALUES (5, 'one'); INSERT INTO PRIMARY_TBL (t) VALUES ('six'); ERROR: null value in column "i" violates not-null constraint DETAIL: Failing row contains (null, six). SELECT '' AS three, * FROM PRIMARY_TBL; three | i | t -------+---+------- | 1 | one | 2 | two | 1 | three | 4 | three | 5 | one (5 rows) DROP TABLE PRIMARY_TBL; -- -- Unique keys -- CREATE TABLE UNIQUE_TBL (i int UNIQUE, t text); INSERT INTO UNIQUE_TBL VALUES (1, 'one'); INSERT INTO UNIQUE_TBL VALUES (2, 'two'); INSERT INTO UNIQUE_TBL VALUES (1, 'three'); ERROR: duplicate key value violates unique constraint "unique_tbl_i_key" DETAIL: Key (i)=(1) already exists. INSERT INTO UNIQUE_TBL VALUES (4, 'four'); INSERT INTO UNIQUE_TBL VALUES (5, 'one'); INSERT INTO UNIQUE_TBL (t) VALUES ('six'); INSERT INTO UNIQUE_TBL (t) VALUES ('seven'); INSERT INTO UNIQUE_TBL VALUES (5, 'five-upsert-insert') ON CONFLICT (i) DO UPDATE SET t = 'five-upsert-update'; INSERT INTO UNIQUE_TBL VALUES (6, 'six-upsert-insert') ON CONFLICT (i) DO UPDATE SET t = 'six-upsert-update'; -- should fail INSERT INTO UNIQUE_TBL VALUES (1, 'a'), (2, 'b'), (2, 'b') ON CONFLICT (i) DO UPDATE SET t = 'fails'; ERROR: ON CONFLICT DO UPDATE command cannot affect row a second time HINT: Ensure that no rows proposed for insertion within the same command have duplicate constrained values. SELECT '' AS five, * FROM UNIQUE_TBL; five | i | t ------+---+-------------------- | 1 | one | 2 | two | 4 | four | | six | | seven | 5 | five-upsert-update | 6 | six-upsert-insert (7 rows) DROP TABLE UNIQUE_TBL; CREATE TABLE UNIQUE_TBL (i int, t text, UNIQUE(i,t)); INSERT INTO UNIQUE_TBL VALUES (1, 'one'); INSERT INTO UNIQUE_TBL VALUES (2, 'two'); INSERT INTO UNIQUE_TBL VALUES (1, 'three'); INSERT INTO UNIQUE_TBL VALUES (1, 'one'); ERROR: duplicate key value violates unique constraint "unique_tbl_i_t_key" DETAIL: Key (i, t)=(1, one) already exists. INSERT INTO UNIQUE_TBL VALUES (5, 'one'); INSERT INTO UNIQUE_TBL (t) VALUES ('six'); SELECT '' AS five, * FROM UNIQUE_TBL; five | i | t ------+---+------- | 1 | one | 2 | two | 1 | three | 5 | one | | six (5 rows) DROP TABLE UNIQUE_TBL; -- -- Deferrable unique constraints -- CREATE TABLE unique_tbl (i int UNIQUE DEFERRABLE, t text); INSERT INTO unique_tbl VALUES (0, 'one'); INSERT INTO unique_tbl VALUES (1, 'two'); INSERT INTO unique_tbl VALUES (2, 'tree'); INSERT INTO unique_tbl VALUES (3, 'four'); INSERT INTO unique_tbl VALUES (4, 'five'); BEGIN; -- default is immediate so this should fail right away UPDATE unique_tbl SET i = 1 WHERE i = 0; ERROR: duplicate key value violates unique constraint "unique_tbl_i_key" DETAIL: Key (i)=(1) already exists. ROLLBACK; -- check is done at end of statement, so this should succeed UPDATE unique_tbl SET i = i+1; SELECT * FROM unique_tbl; i | t ---+------ 1 | one 2 | two 3 | tree 4 | four 5 | five (5 rows) -- explicitly defer the constraint BEGIN; SET CONSTRAINTS unique_tbl_i_key DEFERRED; INSERT INTO unique_tbl VALUES (3, 'three'); DELETE FROM unique_tbl WHERE t = 'tree'; -- makes constraint valid again COMMIT; -- should succeed SELECT * FROM unique_tbl; i | t ---+------- 1 | one 2 | two 4 | four 5 | five 3 | three (5 rows) -- try adding an initially deferred constraint ALTER TABLE unique_tbl DROP CONSTRAINT unique_tbl_i_key; ALTER TABLE unique_tbl ADD CONSTRAINT unique_tbl_i_key UNIQUE (i) DEFERRABLE INITIALLY DEFERRED; BEGIN; INSERT INTO unique_tbl VALUES (1, 'five'); INSERT INTO unique_tbl VALUES (5, 'one'); UPDATE unique_tbl SET i = 4 WHERE i = 2; UPDATE unique_tbl SET i = 2 WHERE i = 4 AND t = 'four'; DELETE FROM unique_tbl WHERE i = 1 AND t = 'one'; DELETE FROM unique_tbl WHERE i = 5 AND t = 'five'; COMMIT; SELECT * FROM unique_tbl; i | t ---+------- 3 | three 1 | five 5 | one 4 | two 2 | four (5 rows) -- should fail at commit-time BEGIN; INSERT INTO unique_tbl VALUES (3, 'Three'); -- should succeed for now COMMIT; -- should fail ERROR: duplicate key value violates unique constraint "unique_tbl_i_key" DETAIL: Key (i)=(3) already exists. -- make constraint check immediate BEGIN; SET CONSTRAINTS ALL IMMEDIATE; INSERT INTO unique_tbl VALUES (3, 'Three'); -- should fail ERROR: duplicate key value violates unique constraint "unique_tbl_i_key" DETAIL: Key (i)=(3) already exists. COMMIT; -- forced check when SET CONSTRAINTS is called BEGIN; SET CONSTRAINTS ALL DEFERRED; INSERT INTO unique_tbl VALUES (3, 'Three'); -- should succeed for now SET CONSTRAINTS ALL IMMEDIATE; -- should fail ERROR: duplicate key value violates unique constraint "unique_tbl_i_key" DETAIL: Key (i)=(3) already exists. COMMIT; -- test deferrable UNIQUE with a partitioned table CREATE TABLE parted_uniq_tbl (i int UNIQUE DEFERRABLE) partition by range (i); CREATE TABLE parted_uniq_tbl_1 PARTITION OF parted_uniq_tbl FOR VALUES FROM (0) TO (10); CREATE TABLE parted_uniq_tbl_2 PARTITION OF parted_uniq_tbl FOR VALUES FROM (20) TO (30); SELECT conname, conrelid::regclass FROM pg_constraint WHERE conname LIKE 'parted_uniq%' ORDER BY conname; conname | conrelid -------------------------+------------------- parted_uniq_tbl_1_i_key | parted_uniq_tbl_1 parted_uniq_tbl_2_i_key | parted_uniq_tbl_2 parted_uniq_tbl_i_key | parted_uniq_tbl (3 rows) BEGIN; INSERT INTO parted_uniq_tbl VALUES (1); SAVEPOINT f; INSERT INTO parted_uniq_tbl VALUES (1); -- unique violation ERROR: duplicate key value violates unique constraint "parted_uniq_tbl_1_i_key" DETAIL: Key (i)=(1) already exists. ROLLBACK TO f; SET CONSTRAINTS parted_uniq_tbl_i_key DEFERRED; INSERT INTO parted_uniq_tbl VALUES (1); -- OK now, fail at commit COMMIT; ERROR: duplicate key value violates unique constraint "parted_uniq_tbl_1_i_key" DETAIL: Key (i)=(1) already exists. DROP TABLE parted_uniq_tbl; -- test a HOT update that invalidates the conflicting tuple. -- the trigger should still fire and catch the violation BEGIN; INSERT INTO unique_tbl VALUES (3, 'Three'); -- should succeed for now UPDATE unique_tbl SET t = 'THREE' WHERE i = 3 AND t = 'Three'; COMMIT; -- should fail ERROR: duplicate key value violates unique constraint "unique_tbl_i_key" DETAIL: Key (i)=(3) already exists. SELECT * FROM unique_tbl; i | t ---+------- 3 | three 1 | five 5 | one 4 | two 2 | four (5 rows) -- test a HOT update that modifies the newly inserted tuple, -- but should succeed because we then remove the other conflicting tuple. BEGIN; INSERT INTO unique_tbl VALUES(3, 'tree'); -- should succeed for now UPDATE unique_tbl SET t = 'threex' WHERE t = 'tree'; DELETE FROM unique_tbl WHERE t = 'three'; SELECT * FROM unique_tbl; i | t ---+-------- 1 | five 5 | one 4 | two 2 | four 3 | threex (5 rows) COMMIT; SELECT * FROM unique_tbl; i | t ---+-------- 1 | five 5 | one 4 | two 2 | four 3 | threex (5 rows) DROP TABLE unique_tbl; -- -- EXCLUDE constraints -- CREATE TABLE circles ( c1 CIRCLE, c2 TEXT, EXCLUDE USING gist (c1 WITH &&, (c2::circle) WITH &&) WHERE (circle_center(c1) <> '(0,0)') ); -- these should succeed because they don't match the index predicate INSERT INTO circles VALUES('<(0,0), 5>', '<(0,0), 5>'); INSERT INTO circles VALUES('<(0,0), 5>', '<(0,0), 4>'); -- succeed INSERT INTO circles VALUES('<(10,10), 10>', '<(0,0), 5>'); -- fail, overlaps INSERT INTO circles VALUES('<(20,20), 10>', '<(0,0), 4>'); ERROR: conflicting key value violates exclusion constraint "circles_c1_c2_excl" DETAIL: Key (c1, (c2::circle))=(<(20,20),10>, <(0,0),4>) conflicts with existing key (c1, (c2::circle))=(<(10,10),10>, <(0,0),5>). -- succeed, because violation is ignored INSERT INTO circles VALUES('<(20,20), 10>', '<(0,0), 4>') ON CONFLICT ON CONSTRAINT circles_c1_c2_excl DO NOTHING; -- fail, because DO UPDATE variant requires unique index INSERT INTO circles VALUES('<(20,20), 10>', '<(0,0), 4>') ON CONFLICT ON CONSTRAINT circles_c1_c2_excl DO UPDATE SET c2 = EXCLUDED.c2; ERROR: ON CONFLICT DO UPDATE not supported with exclusion constraints -- succeed because c1 doesn't overlap INSERT INTO circles VALUES('<(20,20), 1>', '<(0,0), 5>'); -- succeed because c2 doesn't overlap INSERT INTO circles VALUES('<(20,20), 10>', '<(10,10), 5>'); -- should fail on existing data without the WHERE clause ALTER TABLE circles ADD EXCLUDE USING gist (c1 WITH &&, (c2::circle) WITH &&); ERROR: could not create exclusion constraint "circles_c1_c2_excl1" DETAIL: Key (c1, (c2::circle))=(<(0,0),5>, <(0,0),5>) conflicts with key (c1, (c2::circle))=(<(0,0),5>, <(0,0),4>). -- try reindexing an existing constraint REINDEX INDEX circles_c1_c2_excl; DROP TABLE circles; -- Check deferred exclusion constraint CREATE TABLE deferred_excl ( f1 int, f2 int, CONSTRAINT deferred_excl_con EXCLUDE (f1 WITH =) INITIALLY DEFERRED ); INSERT INTO deferred_excl VALUES(1); INSERT INTO deferred_excl VALUES(2); INSERT INTO deferred_excl VALUES(1); -- fail ERROR: conflicting key value violates exclusion constraint "deferred_excl_con" DETAIL: Key (f1)=(1) conflicts with existing key (f1)=(1). INSERT INTO deferred_excl VALUES(1) ON CONFLICT ON CONSTRAINT deferred_excl_con DO NOTHING; -- fail ERROR: ON CONFLICT does not support deferrable unique constraints/exclusion constraints as arbiters BEGIN; INSERT INTO deferred_excl VALUES(2); -- no fail here COMMIT; -- should fail here ERROR: conflicting key value violates exclusion constraint "deferred_excl_con" DETAIL: Key (f1)=(2) conflicts with existing key (f1)=(2). BEGIN; INSERT INTO deferred_excl VALUES(3); INSERT INTO deferred_excl VALUES(3); -- no fail here COMMIT; -- should fail here ERROR: conflicting key value violates exclusion constraint "deferred_excl_con" DETAIL: Key (f1)=(3) conflicts with existing key (f1)=(3). -- bug #13148: deferred constraint versus HOT update BEGIN; INSERT INTO deferred_excl VALUES(2, 1); -- no fail here DELETE FROM deferred_excl WHERE f1 = 2 AND f2 IS NULL; -- remove old row UPDATE deferred_excl SET f2 = 2 WHERE f1 = 2; COMMIT; -- should not fail SELECT * FROM deferred_excl; f1 | f2 ----+---- 1 | 2 | 2 (2 rows) ALTER TABLE deferred_excl DROP CONSTRAINT deferred_excl_con; -- This should fail, but worth testing because of HOT updates UPDATE deferred_excl SET f1 = 3; ALTER TABLE deferred_excl ADD EXCLUDE (f1 WITH =); ERROR: could not create exclusion constraint "deferred_excl_f1_excl" DETAIL: Key (f1)=(3) conflicts with key (f1)=(3). DROP TABLE deferred_excl; -- Comments CREATE TABLE constraint_comments_tbl (a int CONSTRAINT the_constraint CHECK (a > 0)); CREATE DOMAIN constraint_comments_dom AS int CONSTRAINT the_constraint CHECK (value > 0); COMMENT ON CONSTRAINT the_constraint ON constraint_comments_tbl IS 'yes, the comment'; COMMENT ON CONSTRAINT the_constraint ON DOMAIN constraint_comments_dom IS 'yes, another comment'; -- no such constraint COMMENT ON CONSTRAINT no_constraint ON constraint_comments_tbl IS 'yes, the comment'; ERROR: constraint "no_constraint" for table "constraint_comments_tbl" does not exist COMMENT ON CONSTRAINT no_constraint ON DOMAIN constraint_comments_dom IS 'yes, another comment'; ERROR: constraint "no_constraint" for domain constraint_comments_dom does not exist -- no such table/domain COMMENT ON CONSTRAINT the_constraint ON no_comments_tbl IS 'bad comment'; ERROR: relation "no_comments_tbl" does not exist COMMENT ON CONSTRAINT the_constraint ON DOMAIN no_comments_dom IS 'another bad comment'; ERROR: type "no_comments_dom" does not exist COMMENT ON CONSTRAINT the_constraint ON constraint_comments_tbl IS NULL; COMMENT ON CONSTRAINT the_constraint ON DOMAIN constraint_comments_dom IS NULL; DROP TABLE constraint_comments_tbl; DROP DOMAIN constraint_comments_dom;