はてなブックマーク

gistfile1.txt `_� ��:� ishida=# create function any_eq (anyelement, anyelement) returns boolean language sql as 'select $1 = $2'; CREATE FUNCTION ishida=# create operator == (procedure = any_eq, leftarg=anyelement, rightarg=anyelement); CREATE OPERATOR ishida=# select 1+2 == 3; ?column? ---------- t (1 row) ishida=# select 'abc' == 'abc'; ERROR: could not determine polymorphic type because input h