Last updated on March 10th, 2025 at 10:59 pm

Here, we see the Project Employees I LeetCode Solution. This Leetcode problem is solved using MySQL and Pandas.

List of all LeetCode Solution

Level of Question

Easy

Project Employees I LeetCode Solution

1. Problem Statement

Column Name	Type
project_id	int
employee_id	int

(project_id, employee_id) is the primary key of this table. employee_id is a foreign key to Employee table. Each row of this table indicates that the employee with employee_id is working on the project with project_id.

Column Name	Type
employee_id	int
name	varchar
experience_years	int

employee_id is the primary key of this table. It’s guaranteed that experience_years is not NULL. Each row of this table contains information about one employee.

Write an SQL query that reports the average experience years of all the employees for each project, rounded to 2 digits.

Return the result table in any order.

The query result format is in the following example.

Example 1:
Input:

project_id	employee_id
1	1
1	2
1	3
2	1
2	4

employee_id	name	experience_years
1	Khaled	3
2	Ali	2
3	John	1
4	Doe	4

Output:

project_id	average_years
1	2.00
2	2.50

Explanation: The average experience years for the first project is (3 + 2 + 1) / 3 = 2.00 and for the second project is (3 + 2) / 2 = 2.50

2. Code Implementation in Different Languages

2.1 Project Employees I MySQL

select 
  project_id, 
  round(
    avg(experience_years), 
    2
  ) as average_years 
from 
  Project as p 
  left join Employee as e on p.employee_id = e.employee_id 
group by 
  project_id;