Question

Here is my code but im sure its not the correct way of doing this.

mysql_query("SELECT * FROM BlockUsers
WHERE OwnerID =
(SELECT ID FROM UserAccounts WHERE Code='$UserCode')
AND
BlockID =
(SELECT ID FROM UserAccounts WHERE Code='$BlockUserCode')
LIMIT 1", $DB)

Can someone help? thanks!

Answer 1

Yes, but when you’re doing an equality test like that (=, <, >, etc…), the subquery has to return a single value. Otherwise it’d be somevalue = [list of result rows], which makes no sense.

You’d want:

SELECT * FROM BlockUsers
WHERE OwnerID IN (SELECT ID FROM UserAccounts WHERE.....)
              ^^--- use 'in' instead of '=';