mapper.xml相关语法

 <!--    如果存在表  删除表   #和$的区别  $可以防止sql注入 #不行  $是将传入的值直接显示 不会进行转换
    比如  select * from user where name =#{name}  如果name是jack  翻译成 name ='jack'
         select * from user where name =${name}  如果name是jack  翻译成 name = jack
-->

//这里需要注意的是,一般持久层中,查询条件多个两个的时候最好创建一PO模型
 List<UserInfoVo> findByKeywords(Map<String,String) param)
 //如果这里使用了@Param("param")注解的时候,在xml映射中,需要使用param.xxx的方式获取参数

<select id ="findByKeywords" parameterType="java.util.Map" resultType="com.example.test.vo.UserInfoVo>
 SELECT * from user where user_type =1 
 <if test="username != null">
    and username like concat('%',#{username},'%)
 </if>
 
 <!-- 如果持久层中使用注解@Param时候,这里获取参数值的方式为 param.idnumber-->
 <if test="idnumber != null">
    and idnumber like concat('%',#{idnumber},'%')
 </if>
</select>

<select id="getUsersWihtStatus"  resultType="com.wm.adminbackend.entity.user.SysUserDTO">
        SELECT * FROM  sys_user  WHERE status IN
        <foreach collection="ids" item="status" open="(" separator="," close=")" >
            #{status}
        </foreach>
</select>

<update id="updateBatch"  parameterType="java.util.List">  
    <foreach collection="list" item="item" index="index" open="" close="" separator=";">
        update course
        <set>
            name=#{item.name}
        </set>
        where id = #{item.id}
    </foreach>      
</update>

<sql id="Base_Column_List">
    id,name,password,email,phone,address,sex,idnumber
</sql>

<select id="getByIds" resultType="com.haocang.equipment.domain.fault.Fault">
		select
		<include refid="Base_Column_List" />
		from fault a
		where a.state != -1
		and a.id in
		<foreach collection="ids" item="item" separator="," open="("
			close=")">
			#{item,jdbcType=INTEGER}
		</foreach> 
		order by a.id DESC 
	</select>

<insert id="insertSelective" parameterType="repository.entity.user.User" >
    insert into USER 
    <trim prefix="(" suffix=")" suffixOverrides="," >
      <if test="id != null" >
        id,
      </if>
      <if test="userId != null" >
        user_id,
      </if>
    </trim>
    <trim prefix="values (" suffix=")" suffixOverrides="," >
      <if test="id != null" >
        #{id,jdbcType=VARCHAR},
      </if>
      <if test="userId != null" >
        #{userId,jdbcType=VARCHAR},
      </if>
    </trim>
</insert>