mybatis ＜if＞标签 and问题

 <if>标签里的and问题

以前经常用 1=1 来解决拼接and问题，

where
    1 = 1
    <if>and xxx</if>
    <if>and xxx</if>
...

现在用<where>标签即可，如下 

select
    POST_CODE,POST_NAME,REMARK
from POST
<where>
    AND POST_CODE = #{postCode}
    AND POST_NAME = #{postName}
    AND REMARK = #{remark}
</where>

<if>标签直接套在条件外面即可 

SELECT
    POST_CODE,POST_NAME,REMARK
FROM POST
<where>
    <if test="postCode != null and postCode !=''">
        AND POST_CODE = #{postCode}
    </if>
    <if test="postName != null and postName !=''">
        AND POST_NAME= #{postName}
    </if>
    <if test="remark != null and remark!=''">
        AND REMARK = #{remark}
    </if>
</where>

官方文档

mybatis – MyBatis 3 | 动态 SQL

mybatis中避免where空条件后面添加1=1垃圾条件的 优化方法 <where>标签

mybatis where 1=1导致索引失效问题探究_xinpz的博客-CSDN博客_mybatis 索引失效