ado存取文件的有关问题，小弟我新手不太懂

ado存取文件的问题，我新手不太懂

如图，界面上有TADOConnection（名为con1），TADOQuery（名为qry1），TOpenDialog（名为dlgOPen），两个按钮（名为btn1,btn2）。
存入按钮打开一个文件对话框，选取一个文件存入数据库（ado）。
代码怎么实现？下面是我写的，但是插入不了文件。

C/C++ code

//---------------------------------------#include <vcl.h>#pragma hdrstop#include "Unit1.h"#include "ComObj.hpp"//---------------------------------------#pragma package(smart_init)#pragma resource "*.dfm"TForm1 *Form1;//---------------------------------------__fastcall TForm1::TForm1(TComponent* Owner)    : TForm(Owner){}//---------------------------------------void __fastcall TForm1::FormCreate(TObject *Sender){  AnsiString path=ExtractFilePath(Application->ExeName);  Variant CreateAccess;  AnsiString s;  if(!FileExists(Filename))  {    s="Provider=Microsoft.Jet.OLEDB.4.0;Data source="+path+"test.mdb";    CreateAccess=CreateOleObject("ADOX.Catalog");    CreateAccess.OleFunction("Create",s.c_str());    con1->ConnectionString=s;    qry1->SQL->Add("create table mytable1(id int,\                    nodeid int,itemcaption char(255),\                    content binary,Primary Key(id))");    qry1->ExecSQL();    con1->Close();  }  con1->ConnectionString=s;}//---------------------------------------void __fastcall TForm1::btn1Click(TObject *Sender){    if(!dlgOpen1->Execute())        return;    qry1->Open();    qry1->Edit();    qry1->FieldByName("id")->AsInteger = 1;    qry1->FieldByName("nodeid")->AsInteger = 0;    qry1->FieldByName("itemcaption")->AsString = "我的文档";    TMemoryStream *tmpStream = new TMemoryStream();    TBlobField *tmpField;    tmpStream->LoadFromFile(dlgOpen1->FileName);    tmpField = (TBlobField *)qry1->FieldByName("content");    tmpField->LoadFromStream(tmpStream);    qry1->Post();    tmpField = NULL;    delete tmpStream;}//---------------------------------------

C/C++ code

    qry1->SQL->Add("create table mytable1(id int,\                    nodeid int,itemcaption char(255),\                    content OLEObject,Primary Key(id))");