配置文件一mapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="dao.AreaDao">

    <select >
        SELECT area_id,
               area_name,
               area_desc,
               priority,
               create_time,
               last_edit_time
        FROM tb_area
        ORDER BY priority DESC
    </select>

    <insert >
        INSERT INTO tb_area(area_name, area_desc, priority,
                            create_time, last_edit_time)
        VALUES (#{areaName}, #{areaDesc}, #{priority},
                #{createTime}, #{lastEditTime})
    </insert>

    <update >
        update tb_area
        <set>
            <if test="areaName != null">area_name=#{areaName},</if>
            <if test="areaDesc != null">area_desc=#{areaDesc},</if>
            <if test="priority != null">priority=#{priority},</if>
            <if test="lastEditTime != null">last_edit_time=#{lastEditTime}</if>
        </set>
        where area_id=#{areaId}
    </update>

    <delete >
        DELETE
        FROM tb_area
        WHERE area_id =
              #{areaId}
    </delete>

    <delete >
        DELETE FROM
        tb_area
        WHERE area_id IN
        <foreach collection="list" item="areaId" open="(" separator=","
                 close=")">
            #{areaId}
        </foreach>
    </delete>

</mapper>