refactor 1148

Author: fishercoder1534

database/_1148.sql

@@ -1,44 +1 @@
---1148. Article Views I
---
---Table: Views
---
---+---------------+---------+
---| Column Name   | Type    |
---+---------------+---------+
---| article_id    | int     |
---| author_id     | int     |
---| viewer_id     | int     |
---| view_date     | date    |
---+---------------+---------+
---There is no primary key for this table, it may have duplicate rows.
---Each row of this table indicates that some viewer viewed an article (written by some author) on some date.
---Note that equal author_id and viewer_id indicate the same person.
---
---
---Write an SQL query to find all the authors that viewed at least one of their own articles, sorted in ascending order by their id.
---
---The query result format is in the following example:
---
---Views table:
---+------------+-----------+-----------+------------+
---| article_id | author_id | viewer_id | view_date  |
---+------------+-----------+-----------+------------+
---| 1          | 3         | 5         | 2019-08-01 |
---| 1          | 3         | 6         | 2019-08-02 |
---| 2          | 7         | 7         | 2019-08-01 |
---| 2          | 7         | 6         | 2019-08-02 |
---| 4          | 7         | 1         | 2019-07-22 |
---| 3          | 4         | 4         | 2019-07-21 |
---| 3          | 4         | 4         | 2019-07-21 |
---+------------+-----------+-----------+------------+
---
---Result table:
---+------+
---| id   |
---+------+
---| 4    |
---| 7    |
---+------+
-
---# Write your MySQL query statement below
 select distinct(author_id) as id from Views where author_id = viewer_id order by id asc;