我沒有看到這個bug在此實現:函數參數anyelement,PostgreSQL的bug?
CREATE FUNCTION foo(anyelement) RETURNS SETOF int AS $f$
SELECT id FROM unnest(array[1,2,3]) t(id)
WHERE CASE WHEN (pg_typeof($1)::text)='integer' THEN $1::int>2 ELSE true END
$f$ LANGUAGE SQL IMMUTABLE;
SELECT * FROM foo(123); -- OK!
SELECT * FROM foo('test'::text); -- BUG
這是某種形式的PostgreSQL的bug或anyelement
數據類型的無證件的限制?
有趣:隔離CASE
條款時能正常工作:
CREATE FUNCTION bar(anyelement) RETURNS boolean AS $f$
SELECT CASE WHEN (pg_typeof($1)::text)='integer' THEN $1::int>2;
$f$ LANGUAGE SQL IMMUTABLE;
SELECT bar('test'::text), bar(123), bar(1); -- works fine!