"Alexey V. Neyman" <avn@any.ru> writes:
> CREATE TABLE b (
> int4 id
> CHECK (id = ANY(SELECT a.id FROM a))
> );
> ERROR: ExecEvalExpr: unknown expression type 108
More recent versions say
ERROR: Cannot use subselect in CHECK clause
It seems to me that what you really want here is a foreign key
reference, anyway, not a handmade CHECK constraint.
regards, tom lane