Fill month gaps based on multiple columns and aggregate data

Question

I need to aggregate data on a monthly basis and also fill the gaps of months for the whole year with 0 Amounts. The problem is that the aggregation must happen on multiple columns and this makes it tricky (i.e. using date table and left join does not work for me as other data in dataset has matches within different periods that this dataset is missing)

The dataset I have is:

Period	Account	CompanyType	Amount
20220101	11111	Internal	100
20220201	11111	Internal	200
20220601	11111	Internal	300
20221001	11111	Internal	800
20221001	11111	External	100
20221001	11111	External	300
20221201	11111	Internal	100
20220101	22222	External	20
20220601	22222	External	50
20221201	22222	External	30

What i'm looking for is:

Period	Account	Type	Amount
20220101	11111	Internal	100
20220201	11111	Internal	200
20220301	11111	Internal	0
20220401	11111	Internal	0
20220501	11111	Internal	0
20220601	11111	Internal	300
20220701	11111	Internal	0
20220801	11111	Internal	0
20220901	11111	Internal	0
20221001	11111	Internal	800
20221101	11111	Internal	0
20221201	11111	Internal	100
20220101	11111	External	0
20220201	11111	External	0
20220301	11111	External	0
20220401	11111	External	0
20220501	11111	External	0
20220601	11111	External	0
20220701	11111	External	0
20220801	11111	External	0
20220901	11111	External	0
20221001	11111	External	400
20221101	11111	External	0
20221201	11111	External	0
20220101	22222	Internal	20
20220201	22222	Internal	0
20220301	22222	Internal	0
20220401	22222	Internal	0
20220501	22222	Internal	0
20220601	22222	External	50
20220701	22222	External	0
20220801	22222	External	0
20220901	22222	External	0
20221001	22222	External	0
20221101	22222	External	0
20221201	22222	External	30

Lines that are bolded should be created in the result set.

I have tried multiple solutions but just cannot seem to get it to work due to the reason that the dataset has multiple columns and should be aggregated based on all of them (except Amount).

Update: I oversimplified the problem in my example. The sample dataset with all the fields that i am looking into is provided here: Dbfiddle I do have Dates (Calendar) table present and can use it by the way. Note that CompanyType field is tied to Company field and is not relevant in this case.

The result that i am looking for is following: For every combination of ActiveMark, Account, Company(CompanyType), Currency there must be 12 records in total (from January to December). Missing periods should have Amount set as 0

Answer 1

Suppose you have what you've shown to us - one table with data as is.

To get desired result you can use such kind of query:

WITH months(month) AS (
    SELECT * FROM (VALUES (1), (2), (3), (4), (5), (6), (7), (8), (9), (10), (11), (12)) AS m(m)
),
accounts(account) AS (
    SELECT DISTINCT account FROM test
),
companyTypes(companyType) AS (
    SELECT DISTINCT companyType FROM test
),
periods(period) AS (
    SELECT DATEFROMPARTS(2022, month, 01) FROM months WHERE NOT EXISTS (
        SELECT 1 FROM test WHERE MONTH(period) = month
    ) UNION ALL (SELECT DISTINCT period FROM Test)
)
SELECT p.period, a.account, ct.companyType, SUM(COALESCE(t.amount, 0)) 
FROM periods p
CROSS JOIN accounts as a
CROSS JOIN companyTypes as ct
LEFT JOIN test as t ON t.period = p.period AND t.account = a.account AND t.companyType = ct.companyType
GROUP BY p.period, a.account, ct.companyType
ORDER BY a.account, ct.companyType, p.period

Please, check working demo