procedure TForm1.SimpleDataSet1BeforeUpdateRecord(Sender: TObject; 
   SourceDS: TDataSet; DeltaDS: TCustomClientDataSet; UpdateKind: TUpdateKind; 
   var Applied Boolean);
var
  SQL: string;
  Connection: TSQLConnection;
begin
  Connection := (SourceDS as TSimpleDataSet).Connection;
  case UpdateKind of
  ukModify: 
    begin
     { 1st dataset: update Fields[ 1 ], use Fields[ 0 ] in where clause }

      SQL := Format(UpdateStmt1, [DeltaDS.Fields[ 1 ].NewValue, DeltaDS.Fields[ 0 ].OldValue]);
      Connection.Execute(SQL, nil, nil);
     { 2nd dataset: update Fields[ 2 ], use Fields[ 3 ] in where clause }
      SQL := Format(UpdateStmt2, [DeltaDS.Fields[ 2 ].NewValue, DeltaDS.Fields[ 3 ].OldValue]);
      Connection.Execute(SQL, nil, nil);
    end;
  ukDelete: 
    begin
     { 1st dataset: use Fields[ 0 ] in where clause }

      SQL := Format(DeleteStmt1, [DeltaDS.Fields[ 0 ].OldValue]);
      Connection.Execute(SQL, nil, nil);
     { 2nd dataset: use Fields[ 3 ] in where clause }
      SQL := Format(DeleteStmt2, [DeltaDS.Fields[ 3 ].OldValue]);
      Connection.Execute(SQL, nil, nil);
    end;
  ukInsert: 
    begin
     { 1st dataset: values in Fields[ 0 ] and Fields[ 1 ] }
       SQL := Format(InsertStmt1, [DeltaDS.Fields[ 0 ].NewValue, DeltaDS.Fields[ 1 ].NewValue]);

      Connection.Execute(SQL, nil, nil);
     { 2nd dataset: values in Fields[ 2 ] and Fields[ 3 ] }
      SQL := Format(InsertStmt2, [DeltaDS.Fields[ 2 ].NewValue, DeltaDS.Fields[ 3 ].NewValue]);
      Connection.Execute(SQL, nil, nil);
    end;
  end;
  Applied := True;
end;