title: TClientDataset ApplyUpdates error because of database table constraint
body: <p>I have an old Delphi 7 application that loads data from one database table, make many operations and calculation and finally writes records to a destination table.</p>
  
  <p>This old application calls <strong>ApplyUpdates every 500 records</strong>, for performances reasons.</p>
  
  <p>The problem is that, sometimes, in this bunch of records lies one that will trigger database constraint; Delphi fires an <strong>exception on ApplyUpdates</strong>.</p>
  
  <p>My problem is I don't know <strong>which record is responsible</strong> for this exception. There are 500 candidates!</p>
  
  <p>Is it possible to ask TClientDataset which is the offending record?</p>
  
  <p>I do not want to ApplyUpdates foreach appended record for speed issues.</p>