SQL syntax error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'or idDM in (select idDM from danhmuc where cap1 = ) or idDM in (select idDM from' at line 1 — Query: SELECT * FROM sanpham where (idDM =  or idDM in (select idDM from danhmuc where cap1 = ) or idDM in (select idDM from danhmuc where dmCha = ) or idDM in (select idDM from danhmuc where dmCha in (select idDM from danhmuc where cap1 = ))) order by vitri, idSP DESC