add 1378

fishercoder1534 · fishercoder1534 · commit fdf8bfb37017 · 2020-03-14T14:41:53.000-07:00
diff --git a/README.md b/README.md
@@ -923,6 +923,7 @@ _If you like this project, please leave me a star._ &#9733;
 
 |  #  |      Title     |   Solutions   | Video         | Difficulty    | Tag          
 |-----|----------------|---------------|---------------|---------------|-------------
+|1378|[Replace Employee ID With The Unique Identifier](https://leetcode.com/problems/replace-employee-id-with-the-unique-identifier/)|[Solution](../master/database/_1378.sql) || Easy |
 |1369|[Get the Second Most Recent Activity](https://leetcode.com/problems/get-the-second-most-recent-activity/)|[Solution](../master/database/_1369.sql) || Hard |
 |1364|[Number of Trusted Contacts of a Customer](https://leetcode.com/problems/number-of-trusted-contacts-of-a-customer/)|[Solution](../master/database/_1364.sql) || Medium |
 |1355|[Activity Participants](https://leetcode.com/problems/activity-participants/)|[Solution](../master/database/_1355.sql) || Medium |
diff --git a/database/_1378.sql b/database/_1378.sql
@@ -0,0 +1,74 @@
+--1378. 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.
+--
+--# Write your MySQL query statement below
+
+select uni.unique_id, emp.name from Employees emp
+left join
+EmployeeUNI uni
+on emp.id = uni.id
