public SqlDataAdapter TraCuuKhachHang_DA(string tenKH, string diachi) { string sql = ""; if (tenKH.CompareTo("") != 0 && diachi.CompareTo("") != 0) { sql = "select * from Tb_KhachHang where TenKH LIKE @tenKH AND DChi LIKE @diachi"; } else { if (tenKH.CompareTo("") != 0) { sql = "select * from Tb_KhachHang where TenKH LIKE @tenKH"; } else { sql = "select * from Tb_KhachHang where DChi LIKE @diachi"; } } SqlParameter[] thamso = { new SqlParameter("@tenKH", "%" + tenKH + "%"), new SqlParameter("@diachi", "%" + diachi + "%") }; da = ConnectToDB.Truyvan_TraVe_DataAdapter_co_Thamso(sql, thamso); return(da); }