SQL Error: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'or idDM in (select idDM from danhmuc where cap1 = ) or idDM in (select idDM f...' 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