LeetCode（数据库）- 向公司CEO汇报工作的所有人

题目链接：​​点击打开链接​​

题目大意：略。

解题思路：略。

AC 代码

-- 解决方案(1)
SELECT DISTINCT employee_id FROM (
    SELECT employee_id
    FROM Employees WHERE manager_id = 1
    UNION ALL
    SELECT employee_id
    FROM Employees WHERE manager_id IN (
        SELECT employee_id FROM Employees WHERE manager_id = 1
    )
    UNION ALL
    SELECT employee_id
    FROM Employees WHERE manager_id IN (
        SELECT employee_id FROM Employees WHERE manager_id IN (
            SELECT employee_id FROM Employees WHERE manager_id = 1
        )
    )
) T WHERE employee_id != 1

-- 解决方案(2)
SELECT e1.employee_id
FROM Employees e1
JOIN Employees e2 ON e1.manager_id = e2.employee_id
JOIN Employees e3 ON e2.manager_id = e3.employee_id
WHERE e1.employee_id != 1 AND e3.manager_id = 1

-- 解决方案(3)
WITH t1 AS(SELECT employee_id FROM Employees WHERE manager_id = 1),

t2 AS(SELECT employee_id FROM Employees WHERE manager_id IN (SELECT * FROM t1)),

t3 AS(SELECT employee_id FROM Employees WHERE manager_id IN (SELECT * FROM t2))

SELECT * 
FROM t2
WHERE employee_id <> 1
UNION
SELECT * 
FROM t3
WHERE employee_id <> 1