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Our support for multiple-set-clauses in UPDATE assumes that the Params referencing a MULTIEXPR_SUBLINK SubPlan will appear before that SubPlan in the targetlist of the plan node that calculates the updated row. (Yeah, it's a hack...) In some PG branches it's possible that a Result node gets inserted between the primary calculation of the update tlist and the ModifyTable node. setrefs.c did the wrong thing in this case and left the upper-level Params as Params, causing a crash at runtime. What it should do is replace them with "outer" Vars referencing the child plan node's output. That's a result of careless ordering of operations in fix_upper_expr_mutator, so we can fix it just by reordering the code. Fix fix_join_expr_mutator similarly for consistency, even though join nodes could never appear in such a context. (In general, it seems likely to be a bit cheaper to use Vars than Params in such situations anyway, so this patch might offer a tiny performance improvement.) The hazard extends back to 9.5 where the MULTIEXPR_SUBLINK stuff was introduced, so back-patch that far. However, this may be a live bug only in 9.6.x and 10.x, as the other branches don't seem to want to calculate the final tlist below the Result node. (That plan shape change between branches might be a mini-bug in itself, but I'm not really interested in digging into the reasons for that right now. Still, add a regression test memorializing what we expect there, so we'll notice if it changes again.) Per bug report from Eduards Bezverhijs. Discussion: https://postgr.es/m/b6cd572a-3e44-8785-75e9-c512a5a17a73@tieto.com
118 lines
3.5 KiB
SQL
118 lines
3.5 KiB
SQL
--
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-- UPDATE syntax tests
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--
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CREATE TABLE update_test (
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a INT DEFAULT 10,
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b INT,
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c TEXT
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);
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CREATE TABLE upsert_test (
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a INT PRIMARY KEY,
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b TEXT
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);
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INSERT INTO update_test VALUES (5, 10, 'foo');
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INSERT INTO update_test(b, a) VALUES (15, 10);
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SELECT * FROM update_test;
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UPDATE update_test SET a = DEFAULT, b = DEFAULT;
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SELECT * FROM update_test;
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-- aliases for the UPDATE target table
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UPDATE update_test AS t SET b = 10 WHERE t.a = 10;
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SELECT * FROM update_test;
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UPDATE update_test t SET b = t.b + 10 WHERE t.a = 10;
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SELECT * FROM update_test;
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--
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-- Test VALUES in FROM
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--
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UPDATE update_test SET a=v.i FROM (VALUES(100, 20)) AS v(i, j)
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WHERE update_test.b = v.j;
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SELECT * FROM update_test;
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-- fail, wrong data type:
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UPDATE update_test SET a = v.* FROM (VALUES(100, 20)) AS v(i, j)
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WHERE update_test.b = v.j;
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--
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-- Test multiple-set-clause syntax
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--
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INSERT INTO update_test SELECT a,b+1,c FROM update_test;
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SELECT * FROM update_test;
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UPDATE update_test SET (c,b,a) = ('bugle', b+11, DEFAULT) WHERE c = 'foo';
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SELECT * FROM update_test;
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UPDATE update_test SET (c,b) = ('car', a+b), a = a + 1 WHERE a = 10;
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SELECT * FROM update_test;
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-- fail, multi assignment to same column:
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UPDATE update_test SET (c,b) = ('car', a+b), b = a + 1 WHERE a = 10;
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-- uncorrelated sub-select:
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UPDATE update_test
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SET (b,a) = (select a,b from update_test where b = 41 and c = 'car')
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WHERE a = 100 AND b = 20;
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SELECT * FROM update_test;
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-- correlated sub-select:
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UPDATE update_test o
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SET (b,a) = (select a+1,b from update_test i
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where i.a=o.a and i.b=o.b and i.c is not distinct from o.c);
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SELECT * FROM update_test;
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-- fail, multiple rows supplied:
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UPDATE update_test SET (b,a) = (select a+1,b from update_test);
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-- set to null if no rows supplied:
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UPDATE update_test SET (b,a) = (select a+1,b from update_test where a = 1000)
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WHERE a = 11;
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SELECT * FROM update_test;
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-- these should work, but don't yet:
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UPDATE update_test SET (a,b) = (v.*) FROM (VALUES(21, 100)) AS v(i, j)
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WHERE update_test.a = v.i;
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UPDATE update_test SET (a,b) = ROW(v.*) FROM (VALUES(21, 101)) AS v(i, j)
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WHERE update_test.a = v.i;
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-- if an alias for the target table is specified, don't allow references
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-- to the original table name
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UPDATE update_test AS t SET b = update_test.b + 10 WHERE t.a = 10;
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-- Make sure that we can update to a TOASTed value.
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UPDATE update_test SET c = repeat('x', 10000) WHERE c = 'car';
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SELECT a, b, char_length(c) FROM update_test;
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-- Check multi-assignment with a Result node to handle a one-time filter.
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EXPLAIN (VERBOSE, COSTS OFF)
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UPDATE update_test t
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SET (a, b) = (SELECT b, a FROM update_test s WHERE s.a = t.a)
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WHERE CURRENT_USER = SESSION_USER;
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UPDATE update_test t
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SET (a, b) = (SELECT b, a FROM update_test s WHERE s.a = t.a)
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WHERE CURRENT_USER = SESSION_USER;
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SELECT a, b, char_length(c) FROM update_test;
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-- Test ON CONFLICT DO UPDATE
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INSERT INTO upsert_test VALUES(1, 'Boo');
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-- uncorrelated sub-select:
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WITH aaa AS (SELECT 1 AS a, 'Foo' AS b) INSERT INTO upsert_test
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VALUES (1, 'Bar') ON CONFLICT(a)
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DO UPDATE SET (b, a) = (SELECT b, a FROM aaa) RETURNING *;
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-- correlated sub-select:
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INSERT INTO upsert_test VALUES (1, 'Baz') ON CONFLICT(a)
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DO UPDATE SET (b, a) = (SELECT b || ', Correlated', a from upsert_test i WHERE i.a = upsert_test.a)
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RETURNING *;
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-- correlated sub-select (EXCLUDED.* alias):
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INSERT INTO upsert_test VALUES (1, 'Bat') ON CONFLICT(a)
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DO UPDATE SET (b, a) = (SELECT b || ', Excluded', a from upsert_test i WHERE i.a = excluded.a)
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RETURNING *;
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DROP TABLE update_test;
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DROP TABLE upsert_test;
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