mfc与ado

//CoInitialize(NULL);//初始化com库；ado是个com组件，所以得先初始化com库
 //_ConnectionPtr pConn(__uuidof(Connection));//是个指针
 //_RecordsetPtr pRst(__uuidof(Recordset));//是个指针
 // pConn->ConnectionString="PROVIDER=SQLOLEDB;DATA SOURCE=(local);UID=sa;PWD=w?143%adef;DATABASE=Chat";//链接语句期中news为数据库名称
 // pConn->Open("","","",adConnectUnspecified);
 // pRst=pConn->Execute("select * from userinfo",NULL,adCmdText);
 // CString temp;
 // while(!pRst->adoEOF){//第一步中将EOF改为的rsEOF
//  temp= (LPCSTR)((_bstr_t)pRst->GetCollect("username"));
 // 
 // pRst->MoveNext();
 //}
 //pRst->Close();
 //pConn->Close();
 //pRst.Release();
 //pConn.Release();
 //CoUninitialize();//与初始化对应，卸载com库；