Kumar S <ps_postgres(at)yahoo(dot)com> writes:
> My wrong SQL statement:
> update experiment SET samp_id =3 WHERE (select
> exp_slot_name = 4264.dat WHERE exp_slot_id =
> exp_slot_name);
I think you want something like
update experiment SET samp_id = 3
WHERE exp_slot_id = (SELECT exp_slot_id FROM exp_slot_table
WHERE exp_slot_name = '4264.dat');
regards, tom lane