数据库使用步骤。

先把对数据库的操作封装到类ADOConnection，再在App里面调用数据库的操作函数。

在App函数里面的InitInstance（）函数里面打开数据库

ADOConnection m_adoConn;
CUser m_curUser;

InitInstance（）

{

if ( !m_adoConn.Open( GetDBPath()))
{
    AfxMessageBox(_T("Can't open database TrafficLED.mdb."));
    return FALSE;
}

if ( m_adoConn.IsOpen())
{
    m_adoConn.Close();
}

}

其中。

CString CInfoStationApp::GetModulePath()
{
char chPath[MAX_PATH];
char drive[_MAX_DRIVE];
char dir[_MAX_DIR];
GetModuleFileName( NULL , chPath , MAX_PATH ); //得到当前应用程序路径
_splitpath(chPath, drive, dir, NULL,NULL);
CString strPath;
strPath.Format("%s%s", drive, dir);
return strPath;
}

CString CInfoStationApp::GetDBPath()
{
CString strPath = GetModulePath() + _T("TrafficLED.mdb");
return strPath;

}

CString CInfoStationApp::GetIniPath()
{
CString strPath = GetModulePath() + _T("ProgInfo.ini");
return strPath;
}

2.然后登陆

CString strSQL = _T("SELECT * FROM [User]") ;
_RecordsetPtr pRes = theApp.m_adoConn.ExecuteSelectSQL( strSQL );

if ( pRes != NULL )
{
while( !pRes->adoEOF )
{
CString strAdmin = (CString)pRes->GetCollect((_variant_t)((long)0)).bstrVal;
CString strPassword = (CString)pRes->GetCollect((_variant_t)((long)1)).bstrVal;
int nPopedom = (int)pRes->GetCollect((_variant_t)((long)2)).intVal;

m_mapUserPassword.insert( CUserPasswordMap::value_type(strAdmin,strPassword));
m_mapUserPopedom.insert( CUserPopedomMap::value_type(strAdmin,nPopedom));

pRes->MoveNext();    
}
pRes->Close();
pRes.Release();
}

其中，ADOConnection.h 文件为

#pragma once

class ADOConnection
{
public:
	ADOConnection(void);
	virtual ~ADOConnection(void);

public:
    BOOL Open(const CString& strCource) ;
	void Close();
	BOOL IsOpen() ;
	BOOL ExecuteNoSelectSQL(const CString& strSQL);
	_RecordsetPtr ExecuteSelectSQL(const CString& strSQL) ;	
	_ConnectionPtr* GetADOSmartpConnection();

private:
	_ConnectionPtr* m_pConn;
	_ConnectionPtr& m_pConnection;
};

ADOConnection.cpp 文件为　

#include "StdAfx.h"
#include "adoconnection.h"

ADOConnection::ADOConnection(void):m_pConnection(*m_pConn),m_pConn(new _ConnectionPtr)
{
}

ADOConnection::~ADOConnection(void)
{
    this->Close();
    if ( m_pConn != NULL)
    {
        delete m_pConn;
        m_pConn = NULL;
    }
}

BOOL ADOConnection::Open( const CString& strCource )
{
    HRESULT hr = 0;
    try
    {
        hr = CoInitialize(NULL); 
        hr = this->m_pConnection.CreateInstance("ADODB.Connection");
        if (SUCCEEDED(hr))
        {
            // strCource = _T("driver={SQL Server};Server=(local);DATABASE=MessagePublish;UID=sa;PWD=123456") ; //SQL Server连接串
            // strCource = _T("Provider=Microsoft.Jet.OLEDB.4.0;Data Source= MessagePublish.mbd") ; //Access连接串

            
            CString strConn = _T("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=") + strCource + _T(";Jet OLEDB:Database Password=!@#$%^&*()_+;") ;       

            hr = m_pConnection->Open( _bstr_t(strConn),"","",adModeUnknown);  //SQL Server    
            if ( this->IsOpen())
                return TRUE;
        }
    }
    catch (_com_error e)
    {
        return FALSE;
    }
    return FALSE;
}

void ADOConnection::Close()
{
    try
    {
        if( m_pConnection != NULL )
        {
            if ( m_pConnection->State != adStateClosed  )
            {
                m_pConnection->Close();
            }    
            CoUninitialize();
        }
        m_pConnection = NULL; 

    }
    catch (_com_error e)
    {

    }
}

BOOL ADOConnection::IsOpen()
{
    if( m_pConnection == NULL || m_pConnection->State == adStateClosed )
    {
        return FALSE;
    }
    return TRUE;
}

BOOL ADOConnection::ExecuteNoSelectSQL( const CString& strSQL )
{
    try
    {
        _variant_t RecordsAffected;
        m_pConnection->Execute(_bstr_t(strSQL),&RecordsAffected,adCmdText);
        ULONG iInfluence = (long)RecordsAffected;    
        return TRUE;    
    }
    catch (_com_error e)
    {
        CString str =  _T ( "执行SQL语句出错:" ) + strSQL ;
        //AfxMessageBox( str );

        return FALSE;    

    }    
}

_RecordsetPtr ADOConnection::ExecuteSelectSQL( const CString& strSQL )
{
    try
    {    
        _RecordsetPtr m_pRecordset;
        m_pRecordset.CreateInstance(__uuidof(Recordset));
        m_pRecordset->Open(_bstr_t(strSQL)
            ,(IDispatch*)m_pConnection
            ,adOpenDynamic
            ,adLockOptimistic
            ,adCmdText);

        return m_pRecordset;
    }
    catch (_com_error e)
    {

    }

    return NULL;
}

_ConnectionPtr* ADOConnection::GetADOSmartpConnection()
{
    return m_pConn;
}

要遍历数据库里面的数据：

void CInfoStationDlg::GetAllSign()
 {
     CString strSQL =  _T("SELECT * FROM [Sign]") ;
     _RecordsetPtr  pRecordSet = theApp.m_adoConn.ExecuteSelectSQL( strSQL );//这里判断有没有成功打开数据库，如果成功的话，就返回一个对象；
     if (pRecordSet != NULL)
     {        
         while ( !pRecordSet->adoEOF )
         {
             CString strID= (CString)pRecordSet->GetCollect((_variant_t)((long)0)).bstrVal ;
             CString strIP= (CString)pRecordSet->GetCollect((_variant_t)((long)1)).bstrVal ;
             CString strMemo= (CString)pRecordSet->GetCollect((_variant_t)((long)2)).bstrVal ;    

             CSign* pSign = new CSign();
             if ( pSign != NULL )
             {
                 pSign->SetID( strID );
                 pSign->SetIP( strIP );
                 pSign->SetMemo( strMemo);
                 m_listSign.AddTail( pSign );
             }
             pRecordSet->MoveNext();
         }
     }
 }

3增加数据

void CInfoStationDlg::OnBnClickedAdd()
{    
    CSign* pSign = new CSign();
    if ( pSign != NULL )
    {
        CDlgSign dlg( pSign , FALSE , this);
        if ( IDOK == dlg.DoModal())
        {    
            if ( theApp.m_adoConn.ExecuteNoSelectSQL( pSign->GetAddSQL() ) )//这里代表语句执行成功；
            {
                m_listSign.AddTail( pSign );
                FillSignList();
                m_index = m_listCtrlSign.GetItemCount() - 1 ;
                m_listCtrlSign.SetItemState( m_index , LVIS_SELECTED , LVIS_SELECTED );
                m_listCtrlSign.EnsureVisible( m_index , FALSE );
            }
        }
        else
        {
            delete pSign;
            pSign = NULL;
        }
    }    
}

4.修改数据；

POSITION pos = m_listCtrlSign.GetFirstSelectedItemPosition();
    if ( pos )
    {
        int nIndex = m_listCtrlSign.GetNextSelectedItem(pos);
        m_index = nIndex ;
        CSign* pSign = (CSign*)m_listCtrlSign.GetItemData(nIndex);
        if ( pSign != NULL )
        {
            CString strOldID = pSign->GetID();
            CDlgSign dlg( pSign , TRUE , this);
            if ( IDOK == dlg.DoModal())
            {    
                if ( theApp.m_adoConn.ExecuteNoSelectSQL( pSign->GetModifySQL( strOldID) ) )
                {
                    FillSignList();
                }
            }
            m_listCtrlSign.SetItemState( m_index , LVIS_SELECTED , LVIS_SELECTED );
            BOOL SaveProgram( const CString &strPath );
        }
    }
    else
    {

        if ( m_listCtrlSign.SetItemState( m_listCtrlSign.GetItemCount() - 1 , LVIS_SELECTED , LVIS_SELECTED ))
        {
            OnBnClickedEdit();
        }
        else
            return ;
    }

5.删除数据