Replace Employee ID With The Unique Identifier

Author: Viniciuscoding

Leetcode_1378.sql

@@ -0,0 +1,70 @@
+/* Replace Employee ID With The Unique Identifier
+
+
+Table: Employees
++---------------+---------+
+| Column Name   | Type    |
++---------------+---------+
+| id            | int     |
+| name          | varchar |
++---------------+---------+
+id is the primary key for this table.
+Each row of this table contains the id and the name of an employee in a company.
+
+Table: EmployeeUNI
++---------------+---------+
+| Column Name   | Type    |
++---------------+---------+
+| id            | int     |
+| unique_id     | int     |
++---------------+---------+
+(id, unique_id) is the primary key for this table.
+Each row of this table contains the id and the corresponding unique id of an employee in the company.
+ 
+Write an SQL query to show the unique ID of each user, If a user doesn't have a unique ID replace just show null.
+Return the result table in any order.
+
+The query result format is in the following example:
+
+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         |
++----+-----------+
+
+EmployeeUNI table:
++-----------+----------+
+| unique_id | name     |
++-----------+----------+
+| null      | Alice    |
+| null      | Bob      |
+| 2         | Meir     |
+| 3         | Winston  |
+| 1         | Jonathan |
++-----------+----------+
+
+Alice and Bob don't have a unique ID, We will show null instead.
+The unique ID of Meir is 2.
+The unique ID of Winston is 3.
+The unique ID of Jonathan is 1.
+*/
+
+# MY SOLUTION
+SELECT unique_id, name
+FROM Employees e
+LEFT JOIN EmployeeUNI uni
+ON e.id = uni.id