mybatis判断list不为空

时间:2022-05-23 sayyy 人气:13

mybatis判断list不为空

    <if test="status != null and status.size()>0" >
      and s.orderstatus in 
      <foreach collection="status" item="listItem" open="(" close=")" separator="," >
        #{listItem}
      </foreach>
    </if>

建议对特殊字符进行处理

    <if test="status != null and status.size() &gt; 0" >
      and s.orderstatus in 
      <foreach collection="status" item="listItem" open="(" close=")" separator="," >
        #{listItem}
      </foreach>
    </if>

mybatis判断两个集合是否为空

在工作中遇到mybatis中判断两个集合是否为空，不为空的话遍历；都为空执行 1=0 or 1=0，则查询出来空集合

select login,name,email from users u where
<choose>
    <when test="sameEmailList != null and sameEmailList.size > 0 ">
        email in <foreach collection="sameEmailList" item="email" open="(" separator="," close=")">
        #{email, jdbcType=VARCHAR}
        </foreach>
    </when>
    <otherwise>
        1 = 0
    </otherwise>
</choose>
<choose>
    <when test="sameNameList != null and sameNameList.size > 0">
        or name in <foreach collection="sameNameList" item="name" open="(" separator="," close=")">
        #{name, jdbcType=VARCHAR}
    </foreach>
    </when>
    <otherwise>
        or 1 = 0
    </otherwise>
</choose>
ORDER by name, email ASC

以上为个人经验，希望能给大家一个参考，也希望大家多多支持。

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