syntax error: select * from sanpham where idDM = 'ky' or idDM in (select idDM from danhmuc where cap1 = ky) or idDM in (select idDM from danhmuc where dmCha = ky) or idDM in (select idDM from danhmuc where dmCha in (select idDM from danhmuc where cap1 = ky)) order by vitri, idSP DESC