Mybatis update时判断为空的写法和like的写法

update zendtao_new.customcalendarinfo a
<set>
    <if test="pdu != null">
        a.pduname = #{pdu,jdbcType=VARCHAR},
    </if>
    <if test="name != null">
        a.name = #{name,jdbcType=VARCHAR},
    </if>
    <if test="start != null">
        a.start = #{start,jdbcType=VARCHAR},
    </if>
    <if test="end != null">
        a.end = #{end,jdbcType=VARCHAR},
    </if>
    <if test="title != null">
        a.title = #{title,jdbcType=VARCHAR},
    </if>
    <if test="url != null">
        a.url = #{url,jdbcType=VARCHAR},
    </if>
    <if test="env != null">
        a.env = #{env,jdbcType=VARCHAR},
    </if>
</set>
where
a.relativeguid = #{guid,jdbcType=VARCHAR}
and
a.name like CONCAT('%',#{symbol,jdbcType=VARCHAR},'%')