Subtract grouped aggregate column by another in 3 table join query - sql

Question

I'm pretty new to joinings and advanced querying, what I want to do is to join three tables to make an summary of how many hours an employee has spent on courses (course data is omitted from examples).
!-SQL query is below the example table-!
The query must show:
A unique set of employee name.
Their individual allocated hours.
A sum of their hours spent
And return a final new column showing the allowance left.
"employees" table
id
employee_id
1
"Annachiara Darius"
2
"Samar Rajani"
3
"Taonga Eric"
4
"Tycho Sigdag"
5
"Naevius Matvei"
6
"Theophania Eglantine"
7
"Boro Stanislav"
"accounting" table where hours are recorded
id
employee_id
hours_done
1
1
2.50
2
1
2.80
3
2
5.60
4
2
3.30
5
4
4.50
6
5
8.90
7
6
7.60
8
3
6.50
9
7
1.00
10
5
10.30
11
7
11.50
12
5
5.60
13
7
100.00
14
2
30.00
"allocation" table
id
employee_id
hours_allocated
1
1
12
2
2
16
3
3
20
4
4
15
5
5
10
6
6
7
7
7
8
SELECT ACCOUNTING.EMPLOYEE_ID AS EMPLOYEE_ID,
EMPLOYEE.EMPLOYEE_NAME AS EMPLOYEE_NAME,
ALLOCATED.HOURS_ALLOCATED,
SUM(ACCOUNTING.HOURS_DONE) AS HOURS_SPENT,
SUM(ALLOCATED.HOURS_ALLOCATED - ACCOUNTING.HOURS_DONE) AS ALLOWANCE
FROM PUBLIC.ACCOUNTING ACCOUNTING
INNER JOIN
(SELECT EMPLOYEE_NAME,
EMPLOYEE_ID
FROM PUBLIC.EMPLOYEES GROUP
BY EMPLOYEE_ID) EMPLOYEE ON EMPLOYEE.EMPLOYEE_ID = ACCOUNTING.EMPLOYEE_ID
INNER JOIN
(SELECT HOURS_ALLOCATED,
EMPLOYEE_ID
FROM PUBLIC.ALLOCATION GROUP
BY EMPLOYEE_ID,
HOURS_ALLOCATED) ALLOCATED ON ALLOCATED.EMPLOYEE_ID = ACCOUNTING.EMPLOYEE_ID GROUP
BY ACCOUNTING.EMPLOYEE_ID,
EMPLOYEE_NAME,
ALLOCATED.HOURS_ALLOCATED
ORDER
BY EMPLOYEE_NAME ASC
Result from the query above
employee_id
employee_name
hours_allocated
hours_spent
allowance
1
"Annachiara Darius"
12
5.3
18.7
7
"Boro Stanislav"
8
112.5
-88.5
5
"Naevius Matvei"
10
24.8
5.2
2
"Samar Rajani"
16
38.9
9.1
3
"Taonga Eric"
20
6.5
13.5
6
"Theophania Eglantine"
7
7.6
-0.6
4
"Tycho Sigdag"
15
4.5
10.5
As you can see I've managed to get every column displaying the information I wanted correctly.
The problem:
Allowence column is only correct if the employee has only made one entry in the accounting table.
If employee has more than one entry in accounting the calculation is off/wrong.
The line I use to get the allowance is
SUM(ALLOCATED.HOURS_ALLOCATED - ACCOUNTING.HOURS_DONE) AS ALLOWANCE
I've been trying different stuff but can't seem to manage this part of the query.
How can I incorporate this into the group logic?

Answer 1

The answer was posted in a comment.
ALLOCATED.HOURS_ALLOCATED - SUM(ACCOUNTING.HOURS_DONE) is correct
but not
`SUM(ALLOCATED.HOURS_ALLOCATED - ACCOUNTING.HOURS_DONE)` AS ALLOWANCE