经过ADO访问SQLServer

#import "C:\Program Files\Common Files\System\ado\msado15.dll"\
?no_namespace rename("EOF", "EndOfFile")

?...
?// 初始化数据库
?// 初始化OLE/COM库环境 ，为访问ADO接口做准备
?::CoInitialize(NULL);

?_ConnectionPtr m_pConnection("ADODB.Connection");

?try
?{
??// 创建Connection对象
??m_pConnection.CreateInstance("ADODB.Connection");
??// 设置连接字符串，必须是BSTR型或者_bstr_t类型
??_bstr_t strConnect= "Provider=SQLOLEDB;Server=HostName\\SQLEXPRESS;Database=DBName;uid=sa;pwd=XXX;";
??//若数据库在网络上则Server为形如(192.168.1.5,3340)
??//用户sa和密码123只是针对我的库
??m_pConnection->Open(strConnect, "", "", adModeUnknown);
??if(m_pConnection==NULL)
???cerr << "ERROR: connection open error\n";
?}
?catch(_com_error e)
?{?
??// 显示错误信息
??cerr << "nERROR:" << (char*)e.Description();//抛出异常
??return -1;
?}

?// 可以把m_pRecordset作为全局，后面直接使用，获取_RecordsetPtr
?// 检查相关的表是否存在
?// 1.LogTalbe
?try
?{
??char* check_cmd("...");
??_RecordsetPtr r = m_pConnection->Execute(check_cmd,NULL,1);
?}
?catch(_com_error e)
?{?
??// 显示错误信息
??cerr << "ERROR:" << (char*)e.Description();
??return -1;
?}
?...
?
?int id = (int)m_pRecordset->GetCollect("id");

?string name = string(_com_util::ConvertBSTRToString((_bstr_t)(r->GetCollect("name"))));

?// varbinary
?_variant_t v = rs->GetCollect("varbinary");
?pArray = v.Detach().parray;

?HRESULT hr = SafeArrayAccessData(pArray, (void HUGEP**)&token_info);
?if (FAILED(hr))
?{
??cout << "SafeArrayAccessData error: " << __FILE__ << " " << __LINE__ << endl;
??return -1;
?}
?size = pArray->rgsabound[0].cElements;

?if(g_pConnection->State) g_pConnection->Close();
?g_pConnection = NULL;
?::CoUninitialize();