为什么以下代号执行后并关闭窗口，其它窗口在ClientDataSet.CommandText中使用Insert语名会出错？

Question

为什么以下代号执行后并关闭窗口，其它窗口在CommandText中使用Insert语名会出错？
procedure TZhuanChangEdit.FormCreate(Sender: TObject);
 var
   bargainCDS: TClientDataSet;
begin
   bargainCDS:=TClientDataSet.Create(nil);
   with bargainCDS do
   begin
      RemoteServer:=DM_Client.CDSRemote.RemoteServer;
      ProviderName:=DM_Client.CDSRemote.ProviderName;
      CommandText:='select bargain from ylc_database.dbo.bargain'
                  +' where ok=0 group by bargain';
      Open;
      while not Eof do
      begin
         cboBargain.Items.Add(FieldByName('bargain').AsString);
         Next;
      end;
      Close;
   end;
   FreeAndNil(bargainCDS);
end;

Answer 1

补充：ClientDataSet都是以下代码。
RemoteServer:=DM_Client.CDSRemote.RemoteServer;
ProviderName:=DM_Client.CDSRemote.ProviderName;

Answer 2

如果不执行TZhuanChangEdit.FormCreate中的代码就没有问题。

Answer 3

既然连的是同一个PROVIDER，就没必要重复创建CDS

Answer 4

如下代码问题。分不够，再加。unit Unit3;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, DB, DBClient, MConnect, StdCtrls, Grids, DBGrids;type
  TForm1 = class(TForm)
    DCOMConnection1: TDCOMConnection;
    ClientDataSet1: TClientDataSet;
    DataSource1: TDataSource;
    Button1: TButton;
    Button2: TButton;
    ComboBox1: TComboBox;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  Form1: TForm1;implementation{$R *.dfm}procedure TForm1.Button1Click(Sender: TObject);
 var tmp: TClientDataSet;
begin
   tmp:=TClientDataSet.Create(nil);
   tmp.RemoteServer:=Clientdataset1.RemoteServer;
   tmp.ProviderName:='remotedsp';
   tmp.CommandText:='insert agreement (date,code) values (''2003-4-19'',''t001'')';
   tmp.Execute;  //出现“灾难性故障”错误
   tmp.Free;
end;procedure TForm1.Button2Click(Sender: TObject);
 var tmp: TClientDataSet;
begin
   tmp:=TClientDataSet.Create(nil);
   tmp.RemoteServer:=ClientDataSet1.RemoteServer;
   tmp.ProviderName:='remotedsp';
   tmp.CommandText:='select sim_name from sg_sales.dbo.id08 order by sim_name';
   tmp.Open;
   combobox1.Items.Clear;
   while not tmp.Eof do
   begin
      combobox1.Items.Add(tmp['sim_name']);
      tmp.Next;
   end;
   tmp.Close;
   freeandnil(tmp);
end;end.

Answer 5

以上代码先执行Button2再执行Button1