Joining two MySQL datasets by date as well as id - mysql

Question

I am struggling to find a way to efficently join two datasets using a single query
Dataset one can be returned using the following query:
SELECT hours_person_id, hours_date, hours_job, SUM(hours_value) AS hours
FROM hours
WHERE hours_status = 1
GROUP BY hours_person_id, hours_date, hours_job
which gives a dataset similar to
| 1 | 2020-06-07 | 101 | 25 |
| 1 | 2020-06-07 | 102 | 10 |
| 1 | 2020-06-07 | 103 | 5 |
| 2 | 2020-06-07 | 101 | 30 |
| 2 | 2020-06-07 | 104 | 10 |
From which we can get total hours per week, per job, etc...
Our second dataset gives us the hourly rates for the each person. The problem is that this table contains both historical and future hourly rates, so the join needs to ensure that the rate applies to the correct person_id and date. There could also be more than 1 rate for a person on a date.
The following gives all the rates that are active
SELECT rate_person_id, rate_date, rate_value
FROM rates
WHERE rate_active = 1
Which could look like
| 1 | 2020-01-01 | 20.00 |
| 1 | 2020-05-01 | 25.00 |
| 1 | 2020-07-01 | 22.00 |
| 2 | 2020-01-01 | 22.00 |
| 2 | 2020-05-01 | 24.00 |
| 3 | 2020-05-01 | 20.00 |
| 3 | 2020-05-01 | 21.00 |
| 3 | 2020-07-01 | 18.00 |
So for the hours above the rate from the 2020-05-01 would be the expected result, with the 21.00 value being the result for person_id === 3
Can what I am looking for be done in a single Query, or am I better off Joining two subqueries?
Update
As requested here is a fiddle that represents the above
https://www.db-fiddle.com/f/oiUpTnajY6M6ZTfZgRf4kT/0
As you can see we have a query that returns the correct data, but this query does not scale to our curennt data set (1.8m lines and more sub tables)

Answer 1

So for the hours above the rate from the 2020-05-01 would be the expected result, with the 21.00 value being the result for person_id === 1
From your rates output, person_id = 1 was never on rate value 21.00 .
| 1 | 2020-01-01 | 20.00 |
| 1 | 2020-05-01 | 25.00 |
| 1 | 2020-07-01 | 22.00 |
For 2 active rates for a person, do you need the most recent rate or you need the rate in the month where he worked. If there is no rate for that month then do you want 0 rate or something else.

Answer 2

SELECT h.*,
(SELECT rate_value
FROM rates r
WHERE h.hours_person_id = r.rate_person_id AND
r.date <= h.date
ORDER BY r.date DESC
LIMIT 1
) as rate_value
FROM hours h
I don't see what active has to do with the question, because you need to go back in time. You can then aggregate or do whatever you want once you have the correct rate on the date.