c++ ado 连接sql数据库连接不下

求助c++ ado 连接sql数据库连接不上

C/C++ code

// SurperMarket.cpp : 定义控制台应用程序的入口点。//#include "stdafx.h"#include <iostream>#include <string.h>using namespace std;#undef EOF#import "C:\\Windows\\winsxs\\x86_microsoft-windows-m..ents-mdac-ado15-dll_31bf3856ad364e35_6.1.7600.16385_none_0c0738a9d1fa4647\\msado15.dll" // no_namespace rename("EOF", "EndOfFile")using namespace ADODB;int main(){    int i;    try    {            _ConnectionPtr con;  //主要负责数据库的连接        _RecordsetPtr rec;   //主要负责对记录集的操作        _CommandPtr com;    //主要用来保存SQL语句，使用该对象里保存的SQL语句对数据库进行操作        CoInitialize(NULL);        con.CreateInstance(__uuidof(Connection));         rec.CreateInstance(__uuidof(Recordset));        com.CreateInstance(__uuidof(Command));                con->ConnectionString="provider=sqloledb; server=localhost; database=surpermarket";        con->Open(con->ConnectionString,"sa"," ",-1);                CoUninitialize();    }    catch(_com_error e)    {        cout << e.ErrorMessage() << endl;    }        cin>>i;        return 0;}