EXEED_back/src/main/resources/mapper/QywxDepartmentGroupLinkMapper.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.zh.project0512.mapper.QywxDepartmentGroupLinkMapper">

    <resultMap id="departmentListMap" type="java.util.Map" autoMapping="false">
        <id property="departmentId" column="departmentId"/>
        <result column="departmentName" property="departmentName"/>
        <result column="creatAt" property="creatAt"/>
        <collection property="userList" ofType="java.util.Map" javaType="java.util.List" autoMapping="false">
            <id column="userId" property="userId"/>
            <result column="userName" property="userName"/>
        </collection>
    </resultMap>

    <select id="departmentList" resultMap="departmentListMap">
        SELECT t1.*,t2.name,t3.name as departmentName
        ,t4.id as userId,t4.name as userName
        from qywxDepartmentGroupLink as t1
        LEFT JOIN qywxDepartmentGroup as t2 on t1.groupId = t2.id
        INNER JOIN qywxDepartment as t3 on t3.departmentId = t1.departmentId
        LEFT JOIN user as t4 on t4.main_department = t1.departmentId
        where t2.id = #{groupId}
        GROUP BY groupId, departmentId
        ,userName
        ORDER BY creatAt DESC
    </select>

</mapper>