Total Users Per Day - mysql

Question

Problem
I want to show all users for a specific range lets say from 2020-01-01 to from 2020-01-05.
I have a table user where all users are saved. Imagine following table:
user
id | createdAt
1 2020-01-01
2 2020-01-02
3 2020-01-03
4 2020-01-03
5 2020-01-05
The outcome should be (relating to the above user table):
date | count
2020-01-01 1
2020-01-02 2
2020-01-03 4
2020-01-04 4
2020-01-05 5
What I have so far
I have a query that returns the example above as needed:
SELECT COALESCE((SELECT COUNT(*) FROM user u WHERE DATE(u.createdAt) <= DATE(dates.gen_date) AND u.role = 'USER' GROUP BY dates.gen_date ),0) AS y, dates.gen_date AS x FROM user u, (select * from
(select adddate('1970-01-01',t4*10000 + t3*1000 + t2*100 + t1*10 + t0) gen_date from
(select 0 t0 union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t0,
(select 0 t1 union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t1,
(select 0 t2 union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t2,
(select 0 t3 union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t3,
(select 0 t4 union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t4) v
where gen_date between DATE(?) and DATE(?)) AS dates GROUP BY x;
But the execution of this statement is really slow by huge number of users and a large time range.
I thought also of a materialized view but this would be only the last way out.
Database used: MySql 5.7

Answer 1

Test
SELECT (dates.mindate + INTERVAL (t0.n+10*t1.n+100*t2.n+1000*t3.n) DAY) `date`,
COUNT(users.id) `count`
FROM users,
(SELECT ? mindate, ? maxdate) dates,
(select 0 n union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t0,
(select 0 n union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t1,
(select 0 n union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t2,
(select 0 n union select 1 union select 2) t3
WHERE users.createdAt <= (dates.mindate + INTERVAL (t0.n+10*t1.n+100*t2.n+1000*t3.n) DAY)
GROUP BY `date`
HAVING `date` <= dates.maxdate
ORDER BY `date`
It must be less expensive.