ADO基础知识：BookMark的使用

  Bookmark属性，用于书签的作用，记录当前的记录位置，

   Recordset15Ptr rs;    

    rs.CreateInstance("ADODB.Recordset");
    rs->PutCursorLocation (adUseClient);
    rs->CursorType = adOpenStatic;
    rs->Open("select * From employees ",pConnect.GetInterfacePtr(),adOpenStatic,adLockReadOnly,adCmdText);
    long icount = 0 ; 
    icount = rs->RecordCount;
    _variant_t vtbook;  
    long nums  = 5;
    rs->MoveFirst();
    cout<<"Name:"<<(LPCSTR)(_bstr_t)rs->Fields->Item["firstname"]->Value <<" "<<endl ;
    vtbook =  rs->Bookmark;  //记录这个书签。
    _variant_t vtStart;
    vtStart.vt = VT_I4;
    vtStart.iVal = 0 ; 
    rs->Move(nums ); //这里移动了记录位置，
    cout<<"Name:"<<(LPCSTR)(_bstr_t)rs->Fields->Item["firstname"]->Value <<" "<<endl ;
    
    rs->Bookmark = vtbook;//这里使用书签返回原先的位置。
    cout<<"Bookmark Name:"<<(LPCSTR)(_bstr_t)rs->Fields->Item["firstname"]->Value <<" "<<endl ;
    rs->Close();