Client datasets work with an in-memory snapshot of the data from the source dataset. If the source dataset represents server data, then as time elapses other users may modify that data. The data in the client dataset becomes a less accurate picture of the underlying data. 

Like any other dataset, client datasets have a Refresh method that updates its records to match the current values on the server. However, calling Refresh only works if there are no edits in the change log. Calling Refresh when there are unapplied edits results in an exception. 

Client datasets can also update the data while leaving the change log intact. To do this, call the RefreshRecord method. Unlike the Refresh method, RefreshRecord updates only the current record in the client dataset. RefreshRecord changes the record value originally obtained from the provider but leaves any changes in the change log.

procedure TForm1.ClientDataSet1AfterScroll(DataSet: TDataSet);
begin
if ClientDataSet1.UpdateStatus = usUnModified then
ClientDataSet1.RefreshRecord;
end;

void __fastcall TForm1::ClientDataSet1AfterScroll(TDataSet *DataSet)
{
  if (ClientDataSet1->UpdateStatus == usUnModified)
    ClientDataSet1->RefreshRecord();
}