mybatis中時間比較

<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>