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