My Batis mapper.xml中动态SQL中使用trim标签 if end的场景

左手的ㄟ右手 2022-07-14 08:21 73阅读 0赞

trim标签有点类似于replace效果。

trim 属性

prefix：前缀覆盖并增加其内容

suffix：后缀覆盖并增加其内容

prefixOverrides：前缀判断的条件

suffixOverrides：后缀判断的条件

<update id="updateTest" >  
        UPDATE test   
        <trim prefix="SET" suffixOverrides=",">  
         <if test="name!=null and name!=‘‘">  
         name = \#\{name\},  
         </if>  
         <if test="phone!=null and phone!=‘‘">  
         phone = \#\{phone\},  
         </if>  
         <if test="address!=null and address!=‘‘">  
         address = \#\{address\},  
         </if>  
       </trim>    
        WHERE   
         id = \#\{id\}   
 </update>

输出sql

update test set name = \#\{name\}, phone = \#\{phone\}, address = \#\{address\}   WHERE   
         id = \#\{id\}

<select id="checkUserByPhone" parameterType="User" resultMap="UserMap">  
  select \* from user  
  <trim prefix="WHERE" prefixOverrides="AND | OR">  
   <if test="userId!=null and userId!=‘‘">  
         and user\_id != \#\{userId\}  
         </if>  
   <if test="phone!=null and phone!=‘‘ and state!=‘All‘">  
         and phone = \#\{phone\} and state!=‘X‘  
         </if>  
             
  </trim>  
 </select>

输出sql   select \* from user  WHERE user\_id != \#\{userId\}  and phone = \#\{phone\} and state!=‘X‘