SQL查询获取所有经理

Question

我有一个 SQL 表 worker，其中包含以下字段：

1. id
2. Name
3. Manager id

我试图编写一个查询来获取以下字段的列表（'id'、'name'、'manager id'、'manager name'）

请注意，经理 ID 也属于 工人，即经理也是工人。此外，经理还有一个经理，他再次属于同一个表 - 层次结构可以上升到 n 个经理（未知）。

到目前为止，这是我的查询

SELECT tab1.user_name, tab1.user_id, tab1.manager_id, tab2.name AS manager_name, 1 AS LEVEL FROM (SELECT tab1.name AS user_name, tab1.id AS user_id, manager_id FROM DB.user tab1 WHERE id = 1 AND active = 1) tab1 LEFT JOIN DB.user tab2 ON tab1.manager_id = tab2.id UNION SELECT tab1.user_name, tab1.user_id, tab1.manager_id, tab2.name AS manager_name, 2 AS LEVEL FROM (SELECT tab1.name AS user_name, tab1.id AS user_id, manager_id FROM DB.user tab1 WHERE manager_id = 1 AND active = 1) tab1 LEFT JOIN DB.user tab2 ON tab1.manager_id = tab2.id UNION SELECT tab1.user_name, tab1.user_id, tab1.manager_id, tab2.name AS manager_name, 3 AS LEVEL FROM (SELECT tab1.name AS user_name, tab1.id AS user_id, manager_id FROM DB.user tab1 WHERE manager_id IN (SELECT tab1.id FROM DB.user tab1 WHERE manager_id = 1 AND active = 1) AND active = 1 ) tab1 LEFT JOIN DB.user tab2 ON tab1.manager_id = tab2.id

但这让我的结果达到第 3 级层次结构，而我需要它自我扩展并获取我的结果，无论嵌套存在什么级别。

有人可以帮忙吗。

Answer 1

select w1.id, w1.name, w2.id as manager_id, w2.name as manager_name
from worker as w1 inner join worker w2 on w1.manager_id = w2.id