Calculate total scheduled against total actual in two separate tables - mysql

Question

I have two tables in my schema. The first contains a list of recurring appointments - default_appointments. The second table is actual_appointments - these can be generated from the defaults or individually created so not linked to any default entry.
Example:
default_appointments
id
day_of_week
user_id
appointment_start_time
appointment_end_time
1
1
1
10:00:00
16:00:00
2
4
1
11:30:00
17:30:00
3
6
5
09:00:00
17:00:00
actual_appointments
id
default_appointment_id
user_id
appointment_start
appointment_end
1
1
1
2021-09-13 10:00:00
2021-09-13 16:00:00
2
NULL
1
2021-09-13 11:30:00
2021-09-13 13:30:00
3
6
5
2021-09-18 09:00:00
2021-09-18 17:00:00
I'm looking to calculate the total minutes that were scheduled in against the total that were actually created/generated. So ultimately I'd end up with a query result with this data:
user_id
appointment_date
total_planned_minutes
total_actual_minutes
1
2021-09-13
360
480
1
2021-09-16
360
0
5
2021-09-18
480
480
What would be the best approach here? Hopefully the above makes sense.
Edit
OK so the default_appointments table contains all appointments that are "standard" and are automatically generated. These are what appointments "should" happen every week. So e.g. ID 1, this appointment should occur between 10am and 4pm every Monday. ID 2 should occur between 11:30am an 5:30pm every Thursday.
The actual_appointments table contains a list of all of the appointments which did actually occur. Basically what happens is a default_appointment will automatically generate itself an instance in the actual_appointments table when initially set up. The corresponding default_appointment_id indicates that it links to a default and has not been changed - therefore the times on both will remain the same. The user is free to change these appointments that have been generated by a default, resulting in setting the default_appointment_id to NULL * - or -* can add new appointments unrelated to a default.
So, if on a Monday (day_of_week = 1) I should normally have a default appointment at 10am - 4pm, the total minutes I should have planned based on the defaults are 360 minutes, regardless of what's in the actual_appointments table, I should be planned for those 360 minutes every Monday without fail. If in the system I say - well actually, I didn't have an appointment from 10am - 4pm and instead change it to 10am - 2pm, actual_appointments table will then contain the actual time for the day, and the actual minutes appointed would be 240 minutes.
What I need is to group each of these by the date and user to understand how much time the user had planned for appointments in the default_appointments table vs how much they actually appointed.

Answer 1

Adjusted based on new detail in the question.
Note: I used day_of_week values compatible with default MySQL behavior, where Monday = 2.
The first CTE term (args) provides the search parameters, start date and number of days. The second CTE term (drange) calculates the dates in the range to allow generation of the scheduled appointments within that range.
allrows combines the scheduled and actual appointments via UNION to prepare for aggregation. There are other ways to set this up.
Finally, we aggregate the results per user_id and date.
The test case:
Working Test Case (Updated)
WITH RECURSIVE args (startdate, days) AS (
SELECT DATE('2021-09-13'), 7
)
, drange (adate, days) AS (
SELECT startdate, days-1 FROM args UNION ALL
SELECT adate + INTERVAL '1' DAY, days-1 FROM drange WHERE days > 0
)
, allrows AS (
SELECT da.user_id
, dr.adate
, ROUND(TIME_TO_SEC(TIMEDIFF(da.appointment_end_time, da.appointment_start_time))/60, 0) AS planned
, 0 AS actual
FROM drange AS dr
JOIN default_appointments AS da
ON da.day_of_week = dayofweek(adate)
UNION
SELECT user_id
, DATE(appointment_start) AS xdate
, 0 AS planned
, TIMESTAMPDIFF(MINUTE, appointment_start, appointment_end)
FROM drange AS dr
JOIN actual_appointments aa
ON DATE(appointment_start) = dr.adate
)
SELECT user_id, adate
, SUM(planned) AS planned
, SUM(actual) AS actual
FROM allrows
GROUP BY adate, user_id
;
Result:
+---------+------------+---------+--------+
| user_id | adate | planned | actual |
+---------+------------+---------+--------+
| 1 | 2021-09-13 | 360 | 480 |
| 1 | 2021-09-16 | 360 | 0 |
| 5 | 2021-09-18 | 480 | 480 |
+---------+------------+---------+--------+