mybatis批量更新写法

<update id="updateThisMonthBatch" parameterType="java.util.List">
        UPDATE crew_scheduling
        SET plan_name = CASE title
        <foreach collection="list" item="entity">
          <if test="entity.planName == null">
              WHEN 
          </if>
          <if test="entity.planName != null">
              WHEN #{entity.title} THEN #{entity.planName}
          </if>
        </foreach>
        END , plan_status = CASE title
        <foreach collection="list" item="entity">
            <if test="entity.planStatus == null">
                WHEN #{entity.title} THEN crew_scheduling.plan_status
            </if>
            <if test="entity.planStatus != null">
                WHEN #{entity.title} THEN #{entity.planStatus}
            </if>
        </foreach>
        END , car_num = CASE title
        <foreach collection="list" item="entity">
            <if test="entity.carNum == null">
                WHEN #{entity.title} THEN crew_scheduling.car_num
            </if>
            <if test="entity.carNum != null">
                WHEN #{entity.title} THEN #{entity.carNum}
            </if>
        </foreach>
        END
        WHERE DATE_FORMAT(create_time,'%Y-%m') = DATE_FORMAT(NOW(),'%Y-%m')
    </update>

SET 字段名 = CASE WHEN 字段值 THEN 新字段值 CASE WHEN 字段值 THEN 新字段值......