MySQL Query to get the first user that sums X sales - mysql

Question

I'm looking for help with a query.
I have a users table and a sales table. Sales are stored with their date, amount and quantity.
I need to get the first user that reaches an X sum of amount or Y sum of sales.
So I would need to take the sale date in account in order to know which user gets it first.
Can anyone give me a hand with this query or should I use another approach?
I'm currenlty using MySQL 8.0.32.
Here are some sample tables and an example of what is needed.
Users
id
username
1
user1
2
user2
Sales
id
amount
quantity
date
user_id
1
1000
2
2023-01-05
1
2
1500
3
2023-01-05
2
3
500
1
2023-01-07
1
4
1500
3
2023-01-10
1
5
500
1
2023-01-12
1
6
2500
5
2023-01-12
2
7
1000
2
2023-01-15
1
In this case, lets assume that the goal is the first user to sum >=4000. So user2 would be the winner as it reaches to 4000 before user1 even when at the end user1 sums 4500.
I would expect to get the lists of users untill the date that the first user get to the goal ie:
user_id
sum_amount
date
2
4000
2023-01-12
1
3500
2023-01-12
That would be super, but I could handle getting the first user got to the goal.
Thanks.

Answer 1

For MySql 8.0+ you can use SUM() window function to calculate the running total an sort the rows first by the rows that are equal or greater than 4000 and then the date:
SELECT user_id
FROM sales
ORDER BY SUM(amount) OVER(PARTITION BY user_id ORDER BY date) >= 4000 DESC,
date
LIMIT 1;
For previous versions of MySql use a correlated subquery that emulates the functionality of SUM() window function:
SELECT s1.user_id
FROM sales s1
ORDER BY (SELECT SUM(s2.amount)
FROM sales s2
WHERE s2.user_id = s1.user_id AND s2.date <= s1.date
) >= 4000 DESC,
s1.date
LIMIT 1;
See the demo.