MyBatis开发踩坑之路1

image

ZERO

    持续更新 请关注：https://zorkelvll.cn/blogs/zorkelvll/articles/2018/11/15/1542213094869

背景

  本文主要是介绍在开发过程中，使用mybatis所遇到的坑，仅供自己记录查询以及各位猿友借鉴！

场景3：mybatis-xml动态查询条件中实现if else的效果

SQL写法

    <where>
        <if test="sInfoWindcode != null and sInfoWindcode != ''">
            AND a.s_info_windcode = #{sInfoWindcode}
        </if>
        <if test="sInfoWindcode == null || sInfoWindcode == ''">
            <![CDATA[ LIMIT 50 ]]>
        </if>>
    </where>

或者

    <choose>
        <when test="processStatus != null && processStatus != '' && processStatus != '-110'">
           and process_status = #{processStatus,jdbcType=VARCHAR} 
        </when>
        <otherwise>
            and process_status != 1
        </otherwise>
    </choose>

场景2：mybatis-xml查询条件字段的值是一个数组，也即前端的条件筛选的值可以多个

参数定义：

private String[] marketListBoardName;

SQL写法：

<if test="marketListBoardName != null and marketListBoardName != ''">
  AND ad.MARKET_LISTBOARDNAME IN
  <foreach collection="marketListBoardName" index="index" item="item" open="(" separator="," close=")">
    #{item}
  </foreach>
</if>

场景1：mybatis-xml查询条件字段的值是数字字符串如1或者y，如下写法的判断条件将不起作用

<if test="type == '1'">
  AND a.S_DIV_PROGRESS != '3'
</if>
<if test="type == 'y'">
  AND a.S_DIV_PROGRESS != '3'
</if>

更改为：

<if test='type == "1"'>
  AND a.S_DIV_PROGRESS != '3'
</if>
<if test="type == '1'.toString()">
  AND a.S_DIV_PROGRESS != '3'
</if>
<if test='type == "y"'>
  AND a.S_DIV_PROGRESS != '3'
</if>