# 1729. 求关注者的数量
# https://leetcode-cn.com/problems/find-followers-count/

# SQL架构
Create table If Not Exists Followers(user_id int, follower_id int);
Truncate table Followers;
insert into Followers (user_id, follower_id) values ('0', '1');
insert into Followers (user_id, follower_id) values ('1', '0');
insert into Followers (user_id, follower_id) values ('2', '0');
insert into Followers (user_id, follower_id) values ('2', '1');

# Write your MySQL query statement below
select
    user_id,
    count(*) as followers_count
from
    Followers
group by
    user_id
order by
    user_id;

# clean-up
drop table Followers;