Joseph Shraibman <jks@selectacast.net> writes:
> I want to do this:
> SELECT a, (select x,y,z from table2 where table1.a = table2.w), b, c
> from table1;
> But postgres complains:
> ERROR: Subselect must have only one field
You haven't said what you expect to happen if table2 has zero or
multiple matches to any one table1.a value --- but if you want a
plain inner join you could do
SELECT a, x, y, z, b, c from table1, table2 where table1.a = table2.w;
regards, tom lane