EasyNo. 1978
Employees Whose Manager Left the Company — LeetCode 1978 Python Solution
- Topics
- Database
- Reading time
- 3 min
- Source
- leetcode.com
Table schema
Table: Employees +-------------+----------+ | Column Name | Type | +-------------+----------+ | employee_id | int | | name | varchar | | manager_id | int | | salary | int | +-------------+----------+ In SQL, employee_id is the primary key for this table. This table contains information about the employees, their salary, and the ID of their manager.Example
+-------------+----------+
| Column Name | Type |
+-------------+----------+
| employee_id | int |
| name | varchar |
| manager_id | int |
| salary | int |
+-------------+----------+
In SQL, employee_id is the primary key for this table.
This table contains information about the employees, their salary, and the ID of their manager. Some employees do not have a manager (manager_id is null).Python solution
import duckdb
import pandas as pd
def solution(employees: pd.DataFrame) -> pd.DataFrame:
con = duckdb.connect()
con.register("Employees", employees)
return con.execute("""SELECT e1.employee_id
FROM
Employees AS e1
LEFT JOIN Employees AS e2 ON e1.manager_id = e2.employee_id
WHERE e1.salary < 30000 AND e1.manager_id IS NOT NULL AND e2.employee_id IS NULL
ORDER BY 1;""").df()Complexity
- Time
- O(n log n)(typical)
- Space · auxiliary
- O(n)
Related problems
| No. | Problem | Difficulty |
|---|---|---|
| 0175 | Combine Two Tables | Easy |
| 0176 | Second Highest Salary | Medium |
| 0177 | Nth Highest Salary | Medium |
| 0178 | Rank Scores | Medium |
| 0180 | Consecutive Numbers | Medium |
| 0181 | Employees Earning More Than Their Managers | Easy |
Frequently asked questions
- How hard is LeetCode 1978. Employees Whose Manager Left the Company?
LeetCode 1978. Employees Whose Manager Left the Company is rated Easy on LeetCode.
- What topics does LeetCode 1978. Employees Whose Manager Left the Company cover?
LeetCode 1978. Employees Whose Manager Left the Company is tagged Database on LeetCode.