C # Gets the intersection of two of the DataTable, union, difference

The IEnumerable // <the DataRow> QoId = vDTOld.AsEnumerable () ToList ();.
                //// intersection comparing two data sources
                . // IEnumerable <DataRow> QJJ = vDTOld.AsEnumerable () Intersect (DTNew.AsEnumerable () , DataRowComparer.Default);
                //// intersection of the sets of two data sources      
                // = the DataTable DTJJ QJJ.CopyToDataTable ();


                //// taking the difference of the two data sources set
                // IEnumerable <DataRow> QCJ = vDTOld . . AsEnumerable () the Except (DTNew.AsEnumerable (), DataRowComparer.Default);
                //// set difference of two data sources set
                // the DataTable DTCJ QCJ.CopyToDataTable = ();


                // acquiring two sets of data sources and
                IEnumerable <DataRow> QBJ = vDTOld.AsEnumerable ( ) Union (DTNew.AsEnumerable (), DataRowComparer.Default).;
                // set and two sets of data sources
                DataTable DTBJ = QBJ.CopyToDataTable ();