VC++ 使用ADO操作数据库

>基础环境设置 

初始化com库 使用AfxOleInit()函数，可以在MFC环境中使用.

 

>定义一个connection对象,并登录sqlserver服务器

 Connection15Ptr pConnection;  

pConnection.CreateInstance("ADODB.Connection");

_bstr_t bstr_Connectionstring;

bstr_Connectionstring = SysAllocString(L"Provider=SQLOLEDB.1;Password=sa;Persist Security Info=True;User ID=sa;Initial Catalog=Northwind;Data Source=.");

pConnection->Open(bstr_Connectionstring,_bstr_t(""),_bstr_t(""),adConnectUnspecified );

pConnection->Close();

    

>定义一个RecordSet对象，并查询数据集

 Recordset15Ptr pRecordset; 

    pRecordset.CreateInstance("ADODB.Recordset");

    

    VARIANT vtRecord;

    vtRecord.vt = VT_I4;



    BSTR bstr_CommandText = SysAllocString(L"SELECT * FROM dbo.Employees");

    pRecordset  = pConnection->Execute(bstr_CommandText,&vtRecord,adCmdText );

    

    while(!pRecordset->AdoEOF)

    {

         OutputDebugString( (char*) ((_bstr_t) pRecordset->Fields->Item["FirstName"]->Value));

         OutputDebugString("\n");

        pRecordset->MoveNext();

       

    }

    pRecordset->Close();