syntax error: 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