多条查询sql语句返回多表数据集

  string sql = @"SELECT * FROM dbo.Group_Product  WHERE ProductID='" + 67839 + "';SELECT * FROM dbo.Group_ProductPictures  WHERE ProductID='" + 67839 + "';SELECT ProductID,ProductTitle,ProductName,SalePrice,ListingPrice,MainPicture,SaledItemCount FROM dbo.Group_Product  WHERE RelationID=28085";

            DataSet ds = DbHelper.ExecuteDataSet(sql);