george young <gry(at)ll(dot)mit(dot)edu> writes:
> This query returns zero rows:
> newschm3=# select run_id from s_bake where opset_id not in (select opset_id from opset_steps);
> run_id
> --------
> (0 rows)
> But, by my mistake, table opset_steps has no column "opset_id"!
> Surely it should return an error, or at least a warning, not just an
> empty rowset.
Access to upper-level variables from subqueries is (a) useful and (b)
required by the SQL spec, so we are not going to start throwing warnings
about it.
regards, tom lane