refactor 1369

Author: fishercoder1534

Diff for: database/_1369.sql

@@ -1,48 +1,3 @@
---1369. Get the Second Most Recent Activity
---
---Table: UserActivity
---
---+---------------+---------+
---| Column Name   | Type    |
---+---------------+---------+
---| username      | varchar |
---| activity      | varchar |
---| startDate     | Date    |
---| endDate       | Date    |
---+---------------+---------+
---This table does not contain primary key.
---This table contain information about the activity performed of each user in a period of time.
---A person with username performed a activity from startDate to endDate.
---
---Write an SQL query to show the second most recent activity of each user.
---
---If the user only has one activity, return that one.
---
---A user can't perform more than one activity at the same time. Return the result table in any order.
---
---The query result format is in the following example:
---
---UserActivity table:
---+------------+--------------+-------------+-------------+
---| username   | activity     | startDate   | endDate     |
---+------------+--------------+-------------+-------------+
---| Alice      | Travel       | 2020-02-12  | 2020-02-20  |
---| Alice      | Dancing      | 2020-02-21  | 2020-02-23  |
---| Alice      | Travel       | 2020-02-24  | 2020-02-28  |
---| Bob        | Travel       | 2020-02-11  | 2020-02-18  |
---+------------+--------------+-------------+-------------+
---
---Result table:
---+------------+--------------+-------------+-------------+
---| username   | activity     | startDate   | endDate     |
---+------------+--------------+-------------+-------------+
---| Alice      | Dancing      | 2020-02-21  | 2020-02-23  |
---| Bob        | Travel       | 2020-02-11  | 2020-02-18  |
---+------------+--------------+-------------+-------------+
---
---The most recent activity of Alice is Travel from 2020-02-24 to 2020-02-28, before that she was dancing from 2020-02-21 to 2020-02-23.
---Bob only has one record, we just take that one.
-
 --# Write your MySQL query statement below
 --credit: https://leetcode.com/problems/get-the-second-most-recent-activity/discuss/530992/MySQL-solution-184ms-no-subquery