-- -- UPDATE syntax tests -- CREATE TABLE update_test ( a INT DEFAULT 10, b INT, c TEXT ); CREATE TABLE upsert_test ( a INT PRIMARY KEY, b TEXT ); INSERT INTO update_test VALUES (5, 10, 'foo'); INSERT INTO update_test(b, a) VALUES (15, 10); SELECT * FROM update_test; a | b | c ----+----+----- 5 | 10 | foo 10 | 15 | (2 rows) UPDATE update_test SET a = DEFAULT, b = DEFAULT; SELECT * FROM update_test; a | b | c ----+---+----- 10 | | foo 10 | | (2 rows) -- aliases for the UPDATE target table UPDATE update_test AS t SET b = 10 WHERE t.a = 10; SELECT * FROM update_test; a | b | c ----+----+----- 10 | 10 | foo 10 | 10 | (2 rows) UPDATE update_test t SET b = t.b + 10 WHERE t.a = 10; SELECT * FROM update_test; a | b | c ----+----+----- 10 | 20 | foo 10 | 20 | (2 rows) -- -- Test VALUES in FROM -- UPDATE update_test SET a=v.i FROM (VALUES(100, 20)) AS v(i, j) WHERE update_test.b = v.j; SELECT * FROM update_test; a | b | c -----+----+----- 100 | 20 | foo 100 | 20 | (2 rows) -- -- Test multiple-set-clause syntax -- INSERT INTO update_test SELECT a,b+1,c FROM update_test; SELECT * FROM update_test; a | b | c -----+----+----- 100 | 20 | foo 100 | 20 | 100 | 21 | foo 100 | 21 | (4 rows) UPDATE update_test SET (c,b,a) = ('bugle', b+11, DEFAULT) WHERE c = 'foo'; SELECT * FROM update_test; a | b | c -----+----+------- 100 | 20 | 100 | 21 | 10 | 31 | bugle 10 | 32 | bugle (4 rows) UPDATE update_test SET (c,b) = ('car', a+b), a = a + 1 WHERE a = 10; SELECT * FROM update_test; a | b | c -----+----+----- 100 | 20 | 100 | 21 | 11 | 41 | car 11 | 42 | car (4 rows) -- fail, multi assignment to same column: UPDATE update_test SET (c,b) = ('car', a+b), b = a + 1 WHERE a = 10; ERROR: multiple assignments to same column "b" -- uncorrelated sub-select: UPDATE update_test SET (b,a) = (select a,b from update_test where b = 41 and c = 'car') WHERE a = 100 AND b = 20; SELECT * FROM update_test; a | b | c -----+----+----- 100 | 21 | 11 | 41 | car 11 | 42 | car 41 | 11 | (4 rows) -- correlated sub-select: UPDATE update_test o SET (b,a) = (select a+1,b from update_test i where i.a=o.a and i.b=o.b and i.c is not distinct from o.c); SELECT * FROM update_test; a | b | c ----+-----+----- 21 | 101 | 41 | 12 | car 42 | 12 | car 11 | 42 | (4 rows) -- fail, multiple rows supplied: UPDATE update_test SET (b,a) = (select a+1,b from update_test); ERROR: more than one row returned by a subquery used as an expression -- set to null if no rows supplied: UPDATE update_test SET (b,a) = (select a+1,b from update_test where a = 1000) WHERE a = 11; SELECT * FROM update_test; a | b | c ----+-----+----- 21 | 101 | 41 | 12 | car 42 | 12 | car | | (4 rows) -- if an alias for the target table is specified, don't allow references -- to the original table name UPDATE update_test AS t SET b = update_test.b + 10 WHERE t.a = 10; ERROR: invalid reference to FROM-clause entry for table "update_test" LINE 1: UPDATE update_test AS t SET b = update_test.b + 10 WHERE t.a... ^ HINT: Perhaps you meant to reference the table alias "t". -- Make sure that we can update to a TOASTed value. UPDATE update_test SET c = repeat('x', 10000) WHERE c = 'car'; SELECT a, b, char_length(c) FROM update_test; a | b | char_length ----+-----+------------- 21 | 101 | | | 41 | 12 | 10000 42 | 12 | 10000 (4 rows) -- Test ON CONFLICT DO UPDATE INSERT INTO upsert_test VALUES(1, 'Boo'); -- uncorrelated sub-select: WITH aaa AS (SELECT 1 AS a, 'Foo' AS b) INSERT INTO upsert_test VALUES (1, 'Bar') ON CONFLICT(a) DO UPDATE SET (b, a) = (SELECT b, a FROM aaa) RETURNING *; a | b ---+----- 1 | Foo (1 row) -- correlated sub-select: INSERT INTO upsert_test VALUES (1, 'Baz') ON CONFLICT(a) DO UPDATE SET (b, a) = (SELECT b || ', Correlated', a from upsert_test i WHERE i.a = upsert_test.a) RETURNING *; a | b ---+----------------- 1 | Foo, Correlated (1 row) -- correlated sub-select (EXCLUDED.* alias): INSERT INTO upsert_test VALUES (1, 'Bat') ON CONFLICT(a) DO UPDATE SET (b, a) = (SELECT b || ', Excluded', a from upsert_test i WHERE i.a = excluded.a) RETURNING *; a | b ---+--------------------------- 1 | Foo, Correlated, Excluded (1 row) DROP TABLE update_test; DROP TABLE upsert_test;