ForestBlog/src/resources/mapper/LinkMapper.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">
<!-- 定义了一个名为com.liuyanzhao.ssm.blog.mapper.LinkMapper的命名空间，用于组织SQL语句 -->
<mapper namespace="com.liuyanzhao.ssm.blog.mapper.LinkMapper">
    <!-- 定义了一个resultMap，用于映射数据库列和Java对象属性 -->
    <resultMap id="BaseResultMap" type="com.liuyanzhao.ssm.blog.entity.Link">
        <id column="link_id" property="linkId" jdbcType="INTEGER"/> <!-- 链接ID -->
        <result column="link_url" property="linkUrl" jdbcType="VARCHAR"/> <!-- 链接URL -->
        <result column="link_name" property="linkName" jdbcType="VARCHAR"/> <!-- 链接名称 -->
        <result column="link_image" property="linkImage" jdbcType="VARCHAR"/> <!-- 链接图片 -->
        <result column="link_description" property="linkDescription" jdbcType="VARCHAR"/> <!-- 链接描述 -->
        <result column="link_owner_nickname" property="linkOwnerNickname" jdbcType="VARCHAR"/> <!-- 链接所有者昵称 -->
        <result column="link_owner_contact" property="linkOwnerContact" jdbcType="VARCHAR"/> <!-- 链接所有者联系方式 -->
        <result column="link_update_time" property="linkUpdateTime" jdbcType="TIMESTAMP"/> <!-- 链接更新时间 -->
        <result column="link_create_time" property="linkCreateTime" jdbcType="TIMESTAMP"/> <!-- 链接创建时间 -->
        <result column="link_order" property="linkOrder" jdbcType="INTEGER"/> <!-- 链接排序 -->
        <result column="link_status" property="linkStatus" jdbcType="INTEGER"/> <!-- 链接状态 -->
    </resultMap>

    <!-- 定义了一个SQL片段，用于在其他SQL语句中引用列名 -->
    <sql id="Base_Column_List">
        link_id, link_url, link_name, link_image, link_description, link_owner_nickname,
        link_owner_contact, link_update_time, link_create_time, link_order, link_status
    </sql>

    <!-- 定义了一个SQL片段，用于在其他SQL语句中引用表名 -->
    <sql id="tb">link</sql>

    <!-- 根据ID获取链接 -->
    <select id="getLinkById" resultMap="BaseResultMap" parameterType="java.lang.Integer">
        select
        <include refid="Base_Column_List" />
        from link
        where link_id = #{linkId,jdbcType=INTEGER}
    </select>

    <!-- 根据ID删除链接 -->
    <delete id="deleteById" parameterType="java.lang.Integer">
        delete from link
        where link_id = #{linkId,jdbcType=INTEGER}
    </delete>

    <!-- 插入一个新的链接 -->
    <insert id="insert" parameterType="com.liuyanzhao.ssm.blog.entity.Link" useGeneratedKeys="true" keyProperty="linkId">
        insert into link (link_id, link_url, link_name,
          link_image, link_description, link_owner_nickname,
          link_owner_contact, link_update_time, link_create_time,
          link_order, link_status)
        values (#{linkId,jdbcType=INTEGER}, #{linkUrl,jdbcType=VARCHAR}, #{linkName,jdbcType=VARCHAR},
          #{linkImage,jdbcType=VARCHAR}, #{linkDescription,jdbcType=VARCHAR}, #{linkOwnerNickname,jdbcType=VARCHAR},
          #{linkOwnerContact,jdbcType=VARCHAR}, #{linkUpdateTime,jdbcType=TIMESTAMP}, #{linkCreateTime,jdbcType=TIMESTAMP},
          #{linkOrder,jdbcType=INTEGER}, #{linkStatus,jdbcType=INTEGER})
    </insert>

    <!-- 更新链接信息 -->
    <update id="update" parameterType="com.liuyanzhao.ssm.blog.entity.Link">
        update link
        <set>
            <if test="linkUrl != null" > link_url = #{linkUrl,jdbcType=VARCHAR},</if>
            <if test="linkName != null" >link_name = #{linkName,jdbcType=VARCHAR},</if>
            <if test="linkImage != null" >link_image = #{linkImage,jdbcType=VARCHAR},</if>
            <if test="linkDescription != null" >link_description = #{linkDescription,jdbcType=VARCHAR},</if>
            <if test="linkOwnerNickname != null" >link_owner_nickname = #{linkOwnerNickname,jdbcType=VARCHAR},</if>
            <if test="linkOwnerContact != null" >link_owner_contact = #{linkOwnerContact,jdbcType=VARCHAR},</if>
            <if test="linkUpdateTime != null" >link_update_time = #{linkUpdateTime,jdbcType=TIMESTAMP},</if>
            <if test="linkCreateTime != null" >link_create_time = #{linkCreateTime,jdbcType=TIMESTAMP},</if>
            <if test="linkOrder != null" >link_order = #{linkOrder,jdbcType=INTEGER}, </if>
            <if test="linkStatus != null" >link_status = #{linkStatus,jdbcType=INTEGER},</if>
        </set>
        where link_id = #{linkId,jdbcType=INTEGER}
    </update>

    <!-- 获取链接总数 -->
    <select id="countLink" resultType="Integer">
        SELECT COUNT(*) FROM <include refid="tb"/>
        <where>
            <if test="status!=null">
                link_status=#{status}
            </if>
        </where>
    </select>

    <!-- 获取链接列表 -->
    <select id="listLink" resultType="com.liuyanzhao.ssm.blog.entity.Link">
        SELECT
        <include refid="Base_Column_List"/>
        FROM  <include refid="tb"/>
        <where>
            <if test="status!=null">
                link_status=#{status}
            </if>
        </where>
        ORDER BY link_status ASC,link_order DESC,link_id ASC
    </select>
  
</mapper>