ADO实例

//rename作用：解决EOF重定义问题，dll中定义的EOF和程序定义的EOF冲突
/*no_namespace作用：
#import msado15.dll 生成文件 msado15.tlh，默认是有namespace ADODB {}，
所有内容都包在这个名字空间中，访问时需要输入命名空间；
用了no_namespace 生成的头文件中没有namespace，所有内容是全局的，方便访问。 
也可以使用 using namespace ADODB。
*/
#import "C:\Program Files\Common Files\System\ado\msado15.dll" rename("EOF", "adoEOF") no_namespace
//using namespace ADODB;

/*CONNSTRING生成过程：
新建一个记事本文件，后缀改为udl，然后双击打开，配置好后用记事本打开，即可得到CONNSTRING
*/
#define CONNSTRING "Provider=SQLOLEDB.1;Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=test;Data Source=."


void CMy2014_09_11Dlg::OnBtnSelect() 
{
    //清空listview
    m_ctrlResult.DeleteAllItems();

    //COM初始化
    CoInitialize(NULL);
    
    //定义连接对象的智能指针
    _ConnectionPtr conn;
    //定义记录集对象的智能指针
    _RecordsetPtr  rs;
    
    try
    {
        HRESULT hr;
        
        //创建连接对象（智能指针初始化，. 表示调用智能指针的成员函数）
        //{00000514-0000-0010-8000-00AA006D2EA4}
        hr = conn.CreateInstance("ADODB.Connection"); 
        
        //连接数据库（-> 表示调用智能指针指向对象的成员函数，即调用连接对象的成员函数）
        hr = conn->Open(CONNSTRING, "", "", adConnectUnspecified);
        
        //构造查询语句
        UpdateData(TRUE);
        CString strSQL = "select * from t_student where 1 = 1";
        if (m_strSno.Compare("*") != 0)
        {
            CString strChild = " and sno = '"+ m_strSno +"'";
            strSQL += strChild;
        }
        if (m_strSname.Compare("*") != 0)
        {
            CString strChild = " and sname = '"+ m_strSname +"'";
            strSQL += strChild;
        }
        if (m_strSex.Compare("*") != 0)
        {
            CString strChild = " and sex = '"+ m_strSex +"'";
            strSQL += strChild;
        }
        if (m_strBirthday.Compare("*") != 0)
        {
            CString strChild = " and birthday = '"+ m_strBirthday +"'";
            strSQL += strChild;
        }

        //执行命令
        rs = conn->Execute(strSQL.GetBuffer(0), NULL, adOptionUnspecified);
        
        //获取字段数量
        int nCount = rs->Fields->GetCount();
        
        //获取并输出数据
        HWND hList = m_ctrlResult.GetSafeHwnd();
        LVITEM lvi = {0};
        lvi.mask = LVIF_TEXT;
        while(!rs->adoEOF)
        {
            int nIndex = 0;
            for (int i = 0; i < nCount; i++)
            {
                if (i == 0)
                {
                    lvi.iItem = nIndex;
                    //发送LVM_INSERTITEM消息时，subitem必须为0
                    lvi.iSubItem = i;
                    CString strTmp = (char*)(_bstr_t)rs->Fields->Item[(long)i]->Value;
                    lvi.pszText = strTmp.GetBuffer(0);
                    //返回值为item的索引
                    nIndex = ::SendMessage(hList, LVM_INSERTITEM, 0, (LPARAM)&lvi);
                }
                else
                {
                    lvi.iItem = nIndex;
                    lvi.iSubItem = i;
                    CString strTmp = (char*)(_bstr_t)rs->Fields->Item[(long)i]->Value;
                    lvi.pszText = strTmp.GetBuffer(0);
                    ::SendMessage(hList, LVM_SETITEM, 0, (LPARAM)&lvi);
                }
            }

            rs->MoveNext();
        }
        
    }
    catch (_com_error e)
    {
        MessageBox(e.Description());
    }

    //关闭连接
    conn->Close();

    //COM反初始化
    CoUninitialize();
}