一个用技巧强大的ODBC API 函数访问数据库类

rc == SQL_SUCCESS_WITH_INFO)
    { /*有数据*/
    SQLFreeStmt(hstmt_select,SQL_DROP) ;
    hstmt_select = NULL ;
          return lRet ;
    }
    else if (rc == 100)
    { /*没有数据*/
    SQLFreeStmt(hstmt_select,SQL_DROP) ;
    hstmt_select = NULL ;
          return 0 ;
    }
       else if (rc < 0)
    { /*出错*/
         goto end ;
    }
   }
   else
   { /* SQLExecDirect FALSE */
    goto end ;
  }

end:
  {
      m_sErrMsg = "" ;
         while(SQLError(0,
              0,
        hstmt_select,
                       szSQLSTATE,
        &nErr,
        ErrMsg,
        sizeof(ErrMsg),
        &cbmsg)==SQL_SUCCESS)
         m_sErrMsg += "\t\t" + CString(ErrMsg) +"\n" ;  

   SQLFreeStmt(hstmt_select,SQL_DROP) ;
   hstmt_select = NULL ;
    return -1 ;
  }
}
/*非常有用函数,用在确保语句句柄释放*/
void CWdcDatabase::DropHstmtSelect()
{
if(hstmt_select !=NULL)
{
  SQLFreeStmt(hstmt_select,SQL_DROP) ;
  hstmt_select = NULL ;
}
}

……