Leecode
- Managers with at Least 5 Direct Reports
Problem description
Table: Employee
±------------±--------+
| Column Name | Type |
±------------±--------+
| id | int |
| name | varchar |
| department | varchar |
| managerId | int |
±------------±--------+
id is the primary key (column with unique values) for this table.
Each row of this table indicates the name of an employee, their department, and the id of their manager.
If managerId is null, then the employee does not have a manager.
No employee will be the manager of themself.
Write a solution to find managers with at least five direct reports.
Return the result table in any order.
The result format is in the following example.
Example 1:
Input:
Employee table:
| id | name | department | managerId |
|---|---|---|---|
| 101 | John | A | null |
| 102 | Dan | A | 101 |
| 103 | James | A | 101 |
| 104 | Amy | A | 101 |
| 105 | Anne | A | 101 |
| 106 | Ron | B | 101 |
Output
:
| name |
|---|
| John |
My solution
WITH a AS(
SELECT m.name, COUNT(e.managerId) AS coun
FROM Employee e
JOIN Employee m
ON e.managerId = m.id
GROUP BY e.managerId
)
SELECT a.name
FROM a
WHERE coun >= 5
My failed solution, test case not passed when name=null:
# Write your MySQL query statement below
WITH a AS (
SELECT COUNT(id) AS count_connected, managerId
FROM Employee e
GROUP BY managerId
HAVING COUNT(name) >= 5
)
SELECT e.name
FROM a
JOIN Employee e
ON a.managerId = e.id