mybatis中时间比较

<where>    <if test="start_time!=null and start_time!=‘‘">        /*方法一*/        <![CDATA[AND DATE_FORMAT(start_time, ‘%Y-%m-%d‘)>=  DATE_FORMAT(#{start_time}, ‘%Y-%m-%d‘)]]>    </if>    <if test="end_time!=null and end_time!=‘‘">        /*方法二*/        and end_time<![CDATA[  <=  ]]>#{end_time}    </if></where>