Herding_Hub/chenhai-system/src/main/resources/mapper/system/SysAnswersMapper.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.chenhai.system.mapper.SysAnswersMapper">

    <resultMap type="SysAnswers" id="SysAnswersResult">
        <result property="id"    column="id"    />
        <result property="questionId"    column="question_id"    />
        <result property="userId"    column="user_id"    />
        <result property="username"    column="username"    />
        <result property="nickName"    column="nick_name"    />
        <result property="avatar"    column="avatar"    />
        <result property="content"    column="content"    />
        <result property="createdAt"    column="created_at"    />
        <result property="updatedAt"    column="updated_at"    />
        <result property="images"    column="images"    />
        <result property="parentId"    column="parent_id"    />
        <result property="level"    column="level"    />
        <result property="path"    column="path"    />
        <result property="replyCount"    column="reply_count"    />
        <result property="likeCount"    column="like_count"    />
<!--        &lt;!&ndash; 添加新字段 &ndash;&gt;-->
<!--        <result property="latestReplyContent"    column="latest_reply_content"    />-->
<!--        <result property="latestReplyNickName"    column="latest_reply_nick_name"    />-->
<!--        <result property="latestReplyAvatar"    column="latest_reply_avatar"    />-->
<!--        <result property="latestReplyTime"    column="latest_reply_time"    />-->
    </resultMap>

    <sql id="selectSysAnswersVo">
        select
            a.id,
            a.question_id,
            a.user_id,
            a.username,
            u.nick_name,
            u.avatar,
            a.content,
            a.created_at,
            a.updated_at,
            a.images,
            a.parent_id,
            a.level,
            a.path,
            a.reply_count,
            a.like_count
        from sys_answers a
                 left join sys_user u on a.user_id = u.user_id
    </sql>

    <select id="selectSysAnswersList" parameterType="SysAnswers" resultMap="SysAnswersResult">
        <include refid="selectSysAnswersVo"/>
        <where>
            <if test="questionId != null "> and a.question_id = #{questionId}</if>
            <if test="userId != null  and userId != ''"> and a.user_id = #{userId}</if>
            <if test="username != null  and username != ''"> and a.username like concat('%', #{username}, '%')</if>
            <if test="nickName != null  and nickName != ''"> and u.nick_name like concat('%', #{nickName}, '%')</if>
            <if test="content != null  and content != ''"> and a.content like concat('%', #{content}, '%')</if>
            <if test="parentId != null "> and a.parent_id = #{parentId}</if>
            <if test="level != null "> and a.level = #{level}</if>
            <if test="createdAt != null "> and date(a.created_at) = date(#{createdAt})</if>
            <if test="params.beginTime != null and params.beginTime != ''">
                and date_format(a.created_at,'%y%m%d') &gt;= date_format(#{params.beginTime},'%y%m%d')
            </if>
            <if test="params.endTime != null and params.endTime != ''">
                and date_format(a.created_at,'%y%m%d') &lt;= date_format(#{params.endTime},'%y%m%d')
            </if>
            <if test="images != null  and images != ''"> and a.images like concat('%', #{images}, '%')</if>
        </where>
        order by a.created_at desc
    </select>

    <select id="selectSysAnswersById" parameterType="Long" resultMap="SysAnswersResult">
        <include refid="selectSysAnswersVo"/>
        where a.id = #{id}
    </select>

    <!-- 查询顶级答复列表（parent_id = 0） -->
    <select id="selectRootAnswers" parameterType="Long" resultMap="SysAnswersResult">
        <include refid="selectSysAnswersVo"/>
        where a.question_id = #{questionId} and a.parent_id = 0
        order by a.created_at desc
    </select>

    <!-- 查询子回复列表 -->
    <select id="selectChildrenAnswers" parameterType="Long" resultMap="SysAnswersResult">
        <include refid="selectSysAnswersVo"/>
        where a.parent_id = #{parentId}
        order by a.created_at asc
    </select>

    <!-- 查询答复的完整树结构 -->
    <select id="selectAnswerTree" parameterType="Long" resultMap="SysAnswersResult">
        <include refid="selectSysAnswersVo"/>
        where a.question_id = #{questionId}
        order by a.path, a.created_at asc
    </select>

    <insert id="insertSysAnswers" parameterType="SysAnswers" useGeneratedKeys="true" keyProperty="id">
        insert into sys_answers
        <trim prefix="(" suffix=")" suffixOverrides=",">
            <if test="questionId != null">question_id,</if>
            <if test="userId != null and userId != ''">user_id,</if>
            <if test="username != null and username != ''">username,</if>
            <if test="content != null and content != ''">content,</if>
            <if test="images != null and images != ''">images,</if>
            <if test="parentId != null">parent_id,</if>
            <if test="level != null">level,</if>
            <if test="path != null and path != ''">path,</if>
            <if test="replyCount != null">reply_count,</if>
            <if test="likeCount != null">like_count,</if>
            created_at,
        </trim>
        <trim prefix="values (" suffix=")" suffixOverrides=",">
            <if test="questionId != null">#{questionId},</if>
            <if test="userId != null and userId != ''">#{userId},</if>
            <if test="username != null and username != ''">#{username},</if>
            <if test="content != null and content != ''">#{content},</if>
            <if test="images != null and images != ''">#{images},</if>
            <if test="parentId != null">#{parentId},</if>
            <if test="level != null">#{level},</if>
            <if test="path != null and path != ''">#{path},</if>
            <if test="replyCount != null">#{replyCount},</if>
            <if test="likeCount != null">#{likeCount},</if>
            sysdate(),
        </trim>
    </insert>

    <update id="updateSysAnswers" parameterType="SysAnswers">
        update sys_answers
        <trim prefix="SET" suffixOverrides=",">
            <if test="questionId != null">question_id = #{questionId},</if>
            <if test="userId != null and userId != ''">user_id = #{userId},</if>
            <if test="username != null and username != ''">username = #{username},</if>
<!--            <if test="nickName != null and nickName != ''">nick_name = #{nickName},</if>-->
<!--            <if test="avatar != null and avatar != ''">avatar = #{avatar},</if>-->
            <if test="content != null and content != ''">content = #{content},</if>
            <if test="images != null and images != ''">images = #{images},</if>
            <if test="parentId != null">parent_id = #{parentId},</if>
            <if test="level != null">level = #{level},</if>
            <if test="path != null and path != ''">path = #{path},</if>
            <if test="replyCount != null">reply_count = #{replyCount},</if>
            <if test="likeCount != null">like_count = #{likeCount},</if>
            updated_at = sysdate(),
        </trim>
        where id = #{id}
    </update>

    <!-- 更新答复的回复数量 -->
    <update id="updateReplyCount" parameterType="Long">
        update sys_answers
        set reply_count = (
            select cnt from (
                                select count(*) as cnt
                                from sys_answers
                                where parent_id = #{id}
                            ) as temp
        ),
            updated_at = sysdate()
        where id = #{id}
    </update>

    <!-- 更新点赞数量 -->
    <update id="updateLikeCount">
        update sys_answers
        set like_count = like_count + #{increment},
            updated_at = sysdate()
        where id = #{id}
    </update>

    <delete id="deleteSysAnswersById" parameterType="Long">
        delete from sys_answers where id = #{id}
    </delete>

    <delete id="deleteSysAnswersByIds" parameterType="String">
        delete from sys_answers where id in
        <foreach item="id" collection="array" open="(" separator="," close=")">
            #{id}
        </foreach>
    </delete>

    <delete id="deleteAnswersByQuestionId" parameterType="Long">
        delete from sys_answers where question_id = #{questionId}
    </delete>

    <select id="countAnswersByQuestionId" parameterType="Long" resultType="Long">
        select count(*) from sys_answers where question_id = #{questionId}
    </select>

    <!-- 查询某个答复的所有后代ID（用于级联删除） -->
    <select id="selectDescendantIds" parameterType="Long" resultType="Long">
        select id from sys_answers where path like concat('%/', #{id}, '/%')
    </select>
</mapper>