VC连接SQL2005(例子ADO_2)

(2)    void CADO_2Dlg::OnBtnQuery() 

{

       CoInitialize(NULL);                                                        // 初始化COM库

       _ConnectionPtr pConn(__uuidof(Connection));          // 建立Connection

       _RecordsetPtr pRst(__uuidof(Recordset));          // 建立Recordset

 

       _CommandPtr pCmd(__uuidof(Command));                     // 建立Command

 

       try

       {

              //pConn->ConnectionString = "Provider=SQLOLEDB;Password=XXX;Persist Security Info=True;User ID=sa;Initial Catalog=pubs";       //此句正确

              pConn->ConnectionString = "driver={SQL Server};Server=(local);DATABASE=pubs;UID=sa;PWD=xxx";

              pConn->Open("", "", "", adConnectUnspecified);

 

              //pRst = pConn->Execute("select * from authors", NULL, adCmdText);

              //pRst->Open("select * from authors", _variant_t((IDispatch*) pConn), adOpenDynamic, adLockOptimistic, adCmdText);

              pCmd->put_ActiveConnection(_variant_t((IDispatch*) pConn));

              pCmd->CommandText = "select * from authors";

              pRst = pCmd->Execute(NULL, NULL, adCmdText);

 

 

              while(!pRst->rsEOF)

              {

                     ((CListBox*)GetDlgItem(IDC_LIST1))->AddString((_bstr_t)pRst->GetCollect("au_lname")); //查询au_lname字段

                     pRst->MoveNext();

              }

       }

       catch(_com_error e)

       {

              CString errormessage;

              errormessage.Format("Error: %s", e.ErrorMessage());

              AfxMessageBox(errormessage);

       }

 

       AfxMessageBox("查询结束!");

 

       pRst->Close();

       pConn->Close();

       pRst.Release();                                                               // 释放相应COM接口上的引用计数 

       pConn.Release();

       CoUninitialize();                                                       // 卸载COM库

}