public DataTable LayTheNhanVien(string MaNV) { SqlConnection con = ThaoTacDuLieu.TaoVaMoKetNoi(); string sql = string.Format("SELECT * FROM NHANVIEN, CHUCVU WHERE NHANVIEN.MACV = CHUCVU.MACV AND MANV = '{0}'", MaNV); DataTable thenv = ThaoTacDuLieu.ThucThiTruyVan(sql, con); return(thenv); }