+---------------+---------+
| 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.