二、HeadLineDao.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="com.imooc.o2o.dao.HeadLineDao">
    <select id="queryHeadLine" resultType="com.imooc.o2o.entity.HeadLine">
        SELECT
        line_id,
        line_name,
        line_link,
        line_img,
        priority,
        enable_status,
        create_time,
        last_edit_time
        FROM
        tb_head_line
        <where>
            <if test="headLineCondition.enableStatus!=null">
                and enable_status = #{headLineCondition.enableStatus}
            </if>
        </where>
        ORDER BY
        priority DESC
    </select>
    <select id="queryHeadLineById" resultType="com.imooc.o2o.entity.HeadLine">
        SELECT
        line_id,
        line_name,
        line_link,
        line_img,
        priority,
        enable_status,
        create_time,
        last_edit_time
        FROM
        tb_head_line
        WHERE
        line_id = #{lineId}
    </select>
    <select id="queryHeadLineByIds" resultType="com.imooc.o2o.entity.HeadLine"
        parameterType="long">
        SELECT
        line_id,
        line_name,
        line_link,
        line_img,
        priority,
        enable_status,
        create_time,
        last_edit_time
        FROM
        tb_head_line
        WHERE line_id IN
        <foreach collection="list" item="lineId" open="(" separator=","
            close=")">
            #{lineId}
        </foreach>
    </select>
    <insert id="insertHeadLine" useGeneratedKeys="true" keyProperty="lineId"
        keyColumn="line_id">
        INSERT INTO
        tb_head_line(line_name,line_link,line_img,priority,
        enable_status,
        create_time,last_edit_time)
        VALUES
        (#{lineName},#{lineLink},#{lineImg},#{priority},
        #{enableStatus},#{createTime},#{lastEditTime})
    </insert>
    <update id="updateHeadLine" parameterType="com.imooc.o2o.entity.HeadLine">
        update tb_head_line
        <set>
            <if test="lineName != null">line_name=#{lineName},</if>
            <if test="lineLink != null">line_link=#{lineLink},</if>
            <if test="lineImg != null">line_img=#{lineImg},</if>
            <if test="priority != null">priority=#{priority},</if>
            <if test="enableStatus != null">enable_status=#{enableStatus},</if>
            <if test="lastEditTime != null">last_edit_time=#{lastEditTime}</if>
        </set>
        where line_id=#{lineId}
    </update>
    <delete id="deleteHeadLine">
        DELETE FROM
        tb_head_line
        WHERE
        line_id =
        #{lineId}
    </delete>
    <delete id="batchDeleteHeadLine" parameterType="long">
        DELETE FROM
        tb_head_line
        WHERE line_id IN
        <foreach collection="list" item="lineId" open="(" separator=","
            close=")">
            #{lineId}
        </foreach>
    </delete>

</mapper>