怎么把一个TDataSet对象读入memorystream再作为blob保存到数据库中？

Question

请指教。
最好有相应的例子。
百分相送。

Answer 1

Cross-platform:跨平台
procedure TForm1.Button1Click(Sender: TObject);var
  Stream1, Stream2 : TStream;
begin
  Stream1 := SQLDataSet1.CreateBlobStream(SQLDataSet1.FieldByName('Notes', bmRead);
  try
    ClientDataSet1.Edit;
    Stream2 := ClientDataSet1.CreateBlobStream(ClientDataSet1.FieldByName('Res'), bmReadWrite);
    try
      Stream2.CopyFrom(Stream1, Stream1.Size);
      ClientDataSet1.Post;
    finally
      Stream2.Free;
    end;
  finally
    Stream1.Free;
  end;end;

Answer 2

Windows-only:
procedure TForm1.Button1Click(Sender: TObject);var
  Stream1: TBlobStream;
  Stream2: TStream;
begin
  Stream1 := TBlobStream.Create(Table1Notes, bmRead);
  try
    ClientDataSet1.Edit;
    { here抯 a different way to create a blob stream } 
    Stream2 := ClientDataSet1.CreateBlobStream(ClientDataSet1.FieldByName('Res'), bmReadWrite);
    try
      Stream2.CopyFrom(Stream1, Stream1.Size);
      ClientDataSet1.Post;
    finally
      Stream2.Free;
    end;  finally
    Stream1.Free;
  end;
end;
ps:TStream为TmemoryStream等的父类

Answer 3

up
有人知道怎么做吗？
我要把dataset中的记录都保存到blob中，下回读出来使用的