使用原生ADO进行数据库存取。

使用原生ADO进行数据存储，本例子能够显示，向下翻页，但向上翻页有问题。修改后的存储，删除等都存在问题，各位朋友修改一下，我只当起个抛砖引玉的作用。

//.cpp程序

//---------------------------------------------------------------------------

#include <vcl.h>
#pragma hdrstop

#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
#include <DAO_97.h>

TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
}
//---------------------------------------------------------------------------

void __fastcall TForm1::Button1Click(TObject *Sender)
{
VConnect= CreateOleObject("ADODB.Connection");
// 打开连接
VConnect.OleFunction("Open","Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\ado\bcdemos.mdb;Persist Security Info=False");
}
//---------------------------------------------------------------------------

void __fastcall TForm1::Button2Click(TObject *Sender)
{
   VRecordSet=CreateOleObject("ADODB.RecordSet");
   VRecordSet.OlePropertySet("ActiveConnection",VConnect);
   // 设定指令类型与内容
   VRecordSet.OleFunction("Open","Select * from employee", VConnect); // 执行指令
   ShowRecord();
}
//---------------------------------------------------------------------------
void TForm1::ShowRecord()
{
   txtEmpNo->Text=VarToStr(VRecordSet.OlePropertyGet("Fields","EmpNo"));
   txtLastName->Text=VarToStr(VRecordSet.OlePropertyGet("Fields","LastName"));
   txtFirstName->Text=VarToStr(VRecordSet.OlePropertyGet("Fields","FirstName"));
   txtPhone->Text=VarToStr(VRecordSet.OlePropertyGet("Fields","PhoneExt"));
   txtHireDate->Text=VarToStr(VRecordSet.OlePropertyGet("Fields","HireDate"));
   txtSalary->Text=VarToStr(VRecordSet.OlePropertyGet("Fields","Salary"));
}
void __fastcall TForm1::Button3Click(TObject *Sender)
{
  VRecordSet.OleFunction("Update","LastName",txtLastName->Text);
}
//---------------------------------------------------------------------------

void __fastcall TForm1::Button4Click(TObject *Sender)
{
if (! VRecordSet.OlePropertyGet("BOF") ){
   VRecordSet.OleFunction("MoveFirst") ;
   ShowRecord();
   }
}
//---------------------------------------------------------------------------

void __fastcall TForm1::Button6Click(TObject *Sender)
{
if (! VRecordSet.OlePropertyGet("BOF") ){
   VRecordSet.OleFunction("MovePrevious");
   ShowRecord();
   }
}
//---------------------------------------------------------------------------

void __fastcall TForm1::Button7Click(TObject *Sender)
{
if (! VRecordSet.OlePropertyGet("EOF") ){
   VRecordSet.OleFunction("MoveNext");
   ShowRecord();
   }
}
//---------------------------------------------------------------------------

void __fastcall TForm1::Button5Click(TObject *Sender)
{
//if (! VRecordSet.OlePropertyGet("EOF") ){
   VRecordSet.OleFunction("MoveLast");
   ShowRecord();
//   }
}
//---------------------------------------------------------------------------

//.h程序

//---------------------------------------------------------------------------

#ifndef Unit1H
#define Unit1H
//---------------------------------------------------------------------------
#include <Classes.hpp>
#include <Controls.hpp>
#include <StdCtrls.hpp>
#include <Forms.hpp>
#include <ExtCtrls.hpp>
#include <Graphics.hpp>
#include <ADODB.hpp>
#include <Db.hpp>
#include <ComObj.hpp>
#include <DBGrids.hpp>
#include <Grids.hpp>
//---------------------------------------------------------------------------
class TForm1 : public TForm
{
__published: // IDE-managed Components
        TPanel *Panel1;
        TButton *Button1;
        TButton *Button2;
        TButton *Button3;
        TButton *Button4;
        TButton *Button5;
        TButton *Button6;
        TButton *Button7;
        TLabel *Label1;
        TEdit *txtEmpNo;
        TLabel *Label2;
        TEdit *txtLastName;
        TLabel *Label3;
        TEdit *txtFirstName;
        TLabel *Label4;
        TEdit *txtPhone;
        TLabel *Label5;
        TEdit *txtHireDate;
        TLabel *Label6;
        TEdit *txtSalary;
        void __fastcall Button1Click(TObject *Sender);
        void __fastcall Button2Click(TObject *Sender);
        void __fastcall Button3Click(TObject *Sender);
        void __fastcall Button4Click(TObject *Sender);
        void __fastcall Button6Click(TObject *Sender);
        void __fastcall Button7Click(TObject *Sender);
        void __fastcall Button5Click(TObject *Sender);
        void __fastcall FormCreate(TObject *Sender);
private: // User declarations
        Variant VConnect;
        Variant VRecordSet;
        void  ShowRecord();
public:  // User declarations
        __fastcall TForm1(TComponent* Owner);
};
//---------------------------------------------------------------------------
extern PACKAGE TForm1 *Form1;
//---------------------------------------------------------------------------
#endif