Mark Harrison <mh@pixar.com> writes:
> I've got a query that depends upon two pieces of data from another table for
> use in a where clause.
> scratch1=# select id from p4_versions where
> versionof=(select id from p4_files where p4path like '%/date.txt')
> and
> version=(select headver from p4_files where p4path like '%/date.txt');
Use a row-wise comparison, viz
select id from p4_versions
where (versionof, version) = (select id, headver from p4_files
where p4path like '%/date.txt');
regards, tom lane