Delphi Master-detail Datasets with cached updates - how to loop through all the of the records in the detail dataset

I have a master-details datasets: Order and Order items and both datasets are set to cached updates. The problem is when saving order items I want to update a different table in the database, so do some manual work. I tried to do this with checking

MTOrderItem.UpdatesPending

this part works fi开发者_高级运维ne, but when I try to loop through the items in the dataset with

  with MTOrderItem do
  begin
    First;
    while NOT Eof do 
     .....

only get the filtered OrderItems for the selected Order (Master dataset). How can I loop though all the modified detail (order items) records

Usually details dataset will be reopened when master current record changes, so detail contains only records for current master record.

You should load all detail records and filter it manually with Filter und Filtered properties.

e.g.

Master.OnScroll
    Details.Filter = 'MasterID='+Master.FieldByName(ID).AsString
    Details.Filtered := True