ADO 缓存更新

 if (ADOQuery1->UpdateStatus() == usUnmodified)   return;

 ADOQuery1->UpdateBatch(arAll);

UpdateStatus只能判断当前记录（当前行）的状态，不能判断整个记录集的状态啊.

ClientDataSet1控件有ChangeCount属性可以判断整个数据集的变动数。

if( ClientDataSet1->ChangeCount)

  ClientDataSet1->ApplyUpdates(-1);

FDQuery控件也有ChangeCount

 FDQuery1->ChangeCount;
 FDQuery1->UpdateStatus();
 FDQuery1->ApplyUpdates(-1);

1) duplicate a record - just copy the current record to the end of the
dataset

procedure TMyADODataSet.DuplicateRecord;
  var
    r: TMyADODataSet;
    i: integer;
  begin
    if Active and not IsEmpty then begin
      r := TMyADODataSet.Create(nil);
      r.Clone(Self,ltBatchOptimistic);
      r.SetRecNo(Self.RecNo);
      Append;
      for i := 0 to Fields.Count - 1 do if Fields[i].FieldKind = fkData then
Fields[i].Value := r.Fields[i].Value;
      r.Close;
      r.Free;
    end;
  end;

2) Returns the number of pending records - to use with batchupdate mode

function TMyADODataSet.GetModifiedCount: integer;
  var
    r: _RecordSet;
  begin
    if Active and (LockType = ltBatchOptimistic) then begin
      r := Recordset.Clone(adLockBatchOptimistic);
      r.Filter := adFilterPendingRecords;
      Result := r.RecordCount;
      r.Close;
    end
    else Result := -1;
  end;

c++builder 要#include <adoint.h>