编译连接时出现 无效的描述器索引

        CModifyDlg AddDlg;
    AddDlg.m_nType =0;
    if(AddDlg.DoModal()!=IDOK)
        return ;
    CStudentInfoSet* pStudentSet = new CStudentInfoSet(&theApp.GetDatebase());
    if(!pStudentSet)
        return ;
    CString strSQL;
    strSQL.Format("select *from StudentInfo where StudentID = %d",AddDlg.m_nID);
     
    pStudentSet->Open(AFX_DB_USE_DEFAULT_TYPE,strSQL);
    if(pStudentSet->GetRecordCount() !=0)
    {
        AfxMessageBox(_T("学号不能重复"));
        return ;
    }
    strSQL.Format("insert into StudentInfo values(\'%d\', \'%s \', \'%d\', \'%d \', \'%d\')",
        AddDlg.m_nID, AddDlg.m_strName, AddDlg.m_nEnglish, AddDlg.m_nMath, AddDlg.m_nChinese);
    theApp.GetDatebase().ExecuteSQL(strSQL);
    ShowInfo();

    delete pStudentSet;