set @queryString = 'DROP TEMPORARY TABLE IF EXISTS my_Test';
PREPARE stmt1 FROM @queryString;
EXECUTE stmt1;
deallocate prepare stmt1;
set @queryString = 'CREATE TEMPORARY TABLE my_Test (`Id_Sample` int,`SampleId` varchar(100))';
PREPARE stmt1 FROM @queryString;
EXECUTE stmt1;
deallocate prepare stmt1;
select * from my_Test;

     for r:= 2 to asgSource.RowCount-1 do
      begin
       dmSample.fdSample.Append;
       dmSample.fdSample.FieldByName('SampleId').AsString:= asgSource.Cells[mySample,r];
      end;
      dmSample.fdSample.Post;

set @queryString = 'Update my_Test t1
inner join Sample t2 on t1.SampleId=t2.Name set t1.Id_Sample=t2.Id';
PREPARE stmt1 FROM @queryString;
EXECUTE stmt1;
deallocate prepare stmt1;

   select * from my_Test

          
...
       with dmWell.fdCreateTemp do
            begin
             Prepared  := True;
             Execute;
            end;

    dmWell.fdIncomingPWS.Active := True;
    dmWell.fdIncomingPWS.DisableControls;
     for r:= 2 to asgImportPreview.RowCount-1 do
      begin
       dmWell.fdIncomingPWS.Append;
       dmWell.fdIncomingPWS.FieldByName('SampleId').AsString:= asgImportPreview.Cells[SampleIDCol,r];
       dmWell.fdIncomingPWS.FieldByName('WellName').AsString:= asgImportPreview.Cells[WellIDCol,r];
       dmWell.fdIncomingPWS.FieldByName('ProjectId').AsString:= asgImportPreview.Cells[ProjectIDCol,r];
      end;
      try
       dmWell.fdIncomingPWS.ApplyUpdates(-1);
      finally
       dmWell.fdIncomingPWS.Active:=False;
       dbgIncomingData.Refresh;
       ShowMessage('Verified Sample identificators');
      end;
      dmWell.fdIncomingPWS.EnableControls;

           with dmWell.fdUpdateTemp do
            begin
             Prepared  := True;
             Execute;
            end;

       dmWell.fdIncomingPWS.Active:=True;  // вижу обновленные данные
...