Replace Employee ID With The Unique Identifier

Task: Write a solution to show the unique ID of each user.

Table: Employees

+-------------+-------------+
| Column Name | Type        |
+-------------+-------------+
| id          | INT         |
| name        | varchar(20) |
+-------------+-------------+

Table: EmployeeUNI

+-------------+------+
| Column Name | Type |
+-------------+------+
| id          | INT  |
| unique_id   | INT  |
+-------------+------+

Input: Employees table:

+----+----------+
| id | name     |
+----+----------+
| 1  | Alice    |
| 7  | Bob      |
| 11 | Meir     |
| 90 | Winston  |
| 3  | Jonathan |
+----+----------+

EmployeeUNI table:

+----+-----------+
| id | unique_id |
+----+-----------+
| 3  | 1         |
| 11 | 2         |
| 90 | 3         |
+----+-----------+

Output:

+-----------+----------+
| unique_id | name     |
+-----------+----------+
| null      | Alice    |
| null      | Bob      |
| 2         | Meir     |
| 3         | Winston  |
| 1         | Jonathan |
+-----------+----------+

SELECT eu.unique_id, e.name FROM Employees e LEFT JOIN EmployeeUNI eu ON e.id = eu.id;