In social network like Facebook or Twitter, people send friend requests and accept others' requests as well.
Table request_accepted
+--------------+-------------+------------+ | requester_id | accepter_id | accept_date| |--------------|-------------|------------| | 1 | 2 | 2016_06-03 | | 1 | 3 | 2016-06-08 | | 2 | 3 | 2016-06-08 | | 3 | 4 | 2016-06-09 | +--------------+-------------+------------+ This table holds the data of friend acceptance, while requester_id and accepter_id both are the id of a person.
Write a query to find the the people who has most friends and the most friends number under the following rules:
- It is guaranteed there is only 1 people having the most friends.
- The friend request could only been accepted once, which mean there is no multiple records with the same requester_id and accepter_id value.
For the sample data above, the result is:
Result table: +------+------+ | id | num | |------|------| | 3 | 3 | +------+------+ The person with id '3' is a friend of people '1', '2' and '4', so he has 3 friends in total, which is the most number than any others.
Follow-up:
In the real world, multiple people could have the same most number of friends, can you find all these people in this case?