如何在mysql中的组\u concat子查询中使用select查询

我有三张桌子：

tbl_用户存储所有用户详细信息用户id、名称、地址

user_id    name        address
1         a (shop)      home
2         b (shop)    bakerstreet
3         c (staff)   wallstreet
4         d (staff)    georgia
5         e (staff)    sydney

tbl_用户_组存储用户类型用户id，用户类型：1=店铺所有者，2=员工

user_id    user_type
1             1
2             1
3             2
4             2
5             2

tbl_用户协会持有店铺所有者和员工关系店铺所有者id、员工id

shop_owner_id    staff_id
1                3
1                4
1                5
2                3
2                4

期望结果 我想按如下方式显示员工列表和他们关联的各个店铺：

user_id    staff_name    shop_owner
3          c             a,b  
4          d             a,b
5          e             a

我试着使用上面提到的组_concat。查询如下：

SELECT
u.id                          AS user_id,
u.name                        AS staff_name,
(SELECT GROUP_CONCAT(u.name separator ',') FROM tbl_user u WHERE u.id = ua.shop_owner_id) AS 
shop_owner
FROM tbl_user u
JOIN tbl_user_group ug ON u.id = ug.user_id
LEFT JOIN tbl_user_association ua ON u.id = ua.staff_id
WHERE ug.user_type = 2
GROUP BY u.id

但它返回的是一行人员，如下所示。我哪里出错了

user_id    staff_name  shop_owner
3              c        a
4              d        a
5              e        a

我会这样做：

SELECT
    u.user_id,
    u.name,
    GROUP_CONCAT( so.name )
FROM
    tbl_user_group ug
    INNER JOIN tbl_user u
        ON ( ug.user_id = u.user_id )
    INNER JOIN tbl_user_association ua
        ON ( ua.staff_id = u.user_id )
    INNER JOIN tbl_user so -- here join again the user table to get shop owners names
        ON ( ua.shop_owner_id = so.user_id )
WHERE
    ug.user_type = 2
GROUP BY
    u.user_id;

将tbl_用户u中选择的组_CONCATu.name分隔符“，”替换为组_CONCATu.name分隔符，其中u.id=ua.shop\u owner\u id为shop\u owner，并将其中的组_CONCATu.name分隔符替换为shop\u owner，且替换为WHERE子句u.id=ua.shop\u owner\u id