oracle的分页查询，mabatis的sql配置

<select id="getCardcaseByPage" resultType="Cardcase" >
    select * from (
    select a.*,rownum rn from (
        select * from TAB_SYS_CARDCASE
        where  oper_id = #{operId}
          and  status = 1
        <if test="serchKey != null and serchKey != '' and serchKey != 'null' ">
            and  (phone like '%' || #{serchKey} || '%' or user_name like '%' || #{serchKey} || '%' )
        </if>
        order by id desc
    <![CDATA[
        ) a where rownum <= #{end}
    ) where rn >= #{start}
    ]]>
</select>