refactor 1350

Author: fishercoder1534

Diff for: database/_1350.sql

@@ -1,72 +1 @@
---1350. Students With Invalid Departments
---
---Table: Departments
---
---+---------------+---------+
---| Column Name   | Type    |
---+---------------+---------+
---| id            | int     |
---| name          | varchar |
---+---------------+---------+
---id is the primary key of this table.
---The table has information about the id of each department of a university.
---
---
---Table: Students
---
---+---------------+---------+
---| Column Name   | Type    |
---+---------------+---------+
---| id            | int     |
---| name          | varchar |
---| department_id | int     |
---+---------------+---------+
---id is the primary key of this table.
---The table has information about the id of each student at a university and the id of the department he/she studies at.
---
---
---Write an SQL query to find the id and the name of all students who are enrolled in departments that no longer exists.
---
---Return the result table in any order.
---
---The query result format is in the following example:
---
---Departments table:
---+------+--------------------------+
---| id   | name                     |
---+------+--------------------------+
---| 1    | Electrical Engineering   |
---| 7    | Computer Engineering     |
---| 13   | Bussiness Administration |
---+------+--------------------------+
---
---Students table:
---+------+----------+---------------+
---| id   | name     | department_id |
---+------+----------+---------------+
---| 23   | Alice    | 1             |
---| 1    | Bob      | 7             |
---| 5    | Jennifer | 13            |
---| 2    | John     | 14            |
---| 4    | Jasmine  | 77            |
---| 3    | Steve    | 74            |
---| 6    | Luis     | 1             |
---| 8    | Jonathan | 7             |
---| 7    | Daiana   | 33            |
---| 11   | Madelynn | 1             |
---+------+----------+---------------+
---
---Result table:
---+------+----------+
---| id   | name     |
---+------+----------+
---| 2    | John     |
---| 7    | Daiana   |
---| 4    | Jasmine  |
---| 3    | Steve    |
---+------+----------+
---
---John, Daiana, Steve and Jasmine are enrolled in departments 14, 33, 74 and 77 respectively. department 14, 33, 74 and 77 doesn't exist in the Departments table.
-
---# Write your MySQL query statement below
 select id, name from Students where department_id not in (select id from Departments);