need confirmation on a SELECT statement

Hi everybody, when I run the following SELECT statement on mysql everything's fine ... it fails, however, in InterBase telling me Warning: InterBase: Dynamic SQL Error SQL error code = -104 invalid column reference in /usr/local/apache/htdocs/projects/demoshopibase/showbasket.phtml on line 25 The statement goes here: $sql = "SELECT p.id, p.name, p.price, b.sid, b.artno, count(b.artno) " $sql .= "FROM products p, basket b " $sql .= "WHERE (p.id = b.artno) AND (b.sid = '$sid') " $sql .= "GROUP BY p.id, b.artno " If I want to run it with InterBase, I need to add ALL columns to the GROUP BY clause. Although I am not SQL guru, that seems strange to me. This form works and need somebody to tell me if this is my lach of SQL or a specialty in PHP / InterBase interconnection ... (I couldn't believe that either, to be honest) $sql = "SELECT p.id, p.name, p.price, b.sid, b.artno, count(b.artno) " $sql .= "FROM products p, basket b " $sql .= "WHERE (p.id = b.artno) AND (b.sid = '$sid') " $sql .= "GROUP BY p.id, p.name, p.price, b.sid, b.artno " Does anyone have a clue or can at least direct me to find the clue myself? TIA and Cheers, Arne