src/main/resources/mapper/ChatInformationMapper.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.pt5.pthouduan.mapper.ChatInformationMapper">

    <!-- 插入聊天记录 -->
    <insert id="insertChat" parameterType="com.pt5.pthouduan.entity.ChatInformation" useGeneratedKeys="true" keyProperty="informationid">
        INSERT INTO chat_information (sender_id, receiver_id, content)
        VALUES (#{senderId}, #{receiverId}, #{content})
    </insert>

    <!-- 删除聊天记录 -->
    <delete id="deleteChatById" parameterType="int">
        DELETE FROM chat_information WHERE informationid = #{value}
    </delete>

    <!-- 查询某用户参与的所有聊天记录 -->
    <select id="selectChatsByUser" parameterType="long" resultType="com.pt5.pthouduan.entity.ChatInformation">
        SELECT * FROM chat_information
        WHERE sender_id = #{userId} OR receiver_id = #{userId}
        ORDER BY talk_time ASC
    </select>

    <!-- 查询两个用户之间的聊天记录 -->
    <select id="selectChatsBetweenUsers" parameterType="map" resultType="com.pt5.pthouduan.entity.ChatInformation">
        SELECT * FROM chat_information
        WHERE (sender_id = #{user1} AND receiver_id = #{user2})
           OR (sender_id = #{user2} AND receiver_id = #{user1})
        ORDER BY talk_time ASC
    </select>

</mapper>