Reverse track forced records relationships based on user-defined tagging - sql

Question

I have this table where the tagging [Tag_To] is updated by an algorithm based on Year and Period of coverage. My current task (in question) is to update the Status given the Year.
ID Year Method Period_From Period_To SeqNo Tag_To Status
-----------------------------------------------------------------------------------
10 2019 A 2019-01-01 2019-12-31 1
11 2019 B 2019-01-01 2019-06-30 2 1
12 2019 B 2019-07-01 2019-12-31 3 1
13 2019 C 2019-01-01 2019-06-30 4 2
14 2020 A 2020-01-01 2020-12-31 1
15 2020 B 2020-01-01 2020-06-30 2 1
16 2020 B 2020-07-01 2020-12-31 3 1
17 2020 C 2020-01-01 2020-12-31 4 2,3
18 2021 A 2021-01-01 2021-12-31 1
19 2021 B 2021-01-01 2021-12-31 2 1
20 2021 C 2021-07-01 2021-12-31 3 2
The SeqNo is applied per Year and the Tag_To is done based on period of coverage.
11 and 12 are tagged to 10 since B follows A and their period falls within 10 period coverage.
13 is tagged to 11 since C follows B and the period...
15 and 16 to 14
Also note that 17 is tagged to 15 and 16 (2,3) because 17's coverage spans across the 2 periods of 15 and 16 combined
and so on...
The objective is to update the Status by Year such that each path is considered Closed if the path already has Methods A, B and C (there are actually more methods, but to simplify). Status should be Open for paths that haven't completed the methods.
From the example above, there are 5 paths:
10(A)-->11(B)-->13(C) = Closed
10(A)-->12(B)-->??? = Open
14(A)-->15(B)-->17(C) = Closed
14(A)-->16(B)-->17(C) = Closed
18(A)-->19(B)-->20(C) = Closed
Therefore the status update should be:
ID Year Method Period_From Period_To SeqNo Tag_To Status
-----------------------------------------------------------------------------------
10 2019 A 2019-01-01 2019-12-31 1 Open
11 2019 B 2019-01-01 2019-06-30 2 1 Closed
12 2019 B 2019-07-01 2019-12-31 3 1 Open
13 2019 C 2019-01-01 2019-06-30 4 2 Closed
14 2020 A 2020-01-01 2020-12-31 1 Closed
15 2020 B 2020-01-01 2020-06-30 2 1 Closed
16 2020 B 2020-07-01 2020-12-31 3 1 Closed
17 2020 C 2020-01-01 2020-12-31 4 2,3 Closed
18 2021 A 2021-01-01 2021-12-31 1 Closed
19 2021 B 2021-01-01 2021-12-31 2 1 Closed
20 2021 C 2021-07-01 2021-12-31 3 2 Closed
I hope I have explained everything clearly. Would really appreciate if anyone could help.

Answer 1

Just to update viewers that I have managed to solve this on my own although the solution is super non-dynamic and quite inefficient, it pretty much did the job for me. Here's what I did.
UPDATE Table SET
Status =
CASE WHEN Method = 'B'
AND NOT EXISTS ( SELECT * FROM Table P INNER JOIN
(
SELECT VALUE AS Tag_To
FROM Table AV
CROSS APPLY STRING_SPLIT(AV.Tag_To, ',')
WHERE AV.Method = 'C'
) C ON P.Sequence_No = C.Tag_To
WHERE P.ID = AValue.ID
)
THEN 'Open'
WHEN Method = 'A'
AND NOT EXISTS ( SELECT * FROM Table P INNER JOIN
(
SELECT VALUE AS Tag_To
FROM Table AV
CROSS APPLY STRING_SPLIT(AV.Tag_To, ',')
WHERE AV.Method = 'B'
) C ON P.Sequence_No = C.Tag_To
WHERE P.ID = AValue.ID
)
THEN 'Open'
ELSE 'Closed'
END
FROM Table AValue
WHERE Year = #Year
;WITH CTE AS
(
SELECT
ROW_NUMBER() OVER(PARTITION BY A.Method ORDER BY A.Sequence_No ASC) SN,
A.ID,
A.Method,
A.Sequence_No,
A.Tag_To,
A.Period_From,
A.Period_To,
A.Status
FROM Table A
LEFT JOIN
(
SELECT VALUE AS Tag_To
FROM Table AV
CROSS APPLY STRING_SPLIT(AV.Tag_To, ',')
WHERE Year = #Year
) B ON A.Sequence_No = B.Tag_To
WHERE Year = #Year
),
CTE2 AS
(
SELECT DISTINCT SN FROM CTE
WHERE Status = 'Open'
)
UPDATE Table SET
Status = 'Open'
FROM Table
INNER JOIN CTE ON Table.ID = CTE.ID
INNER JOIN CTE2 ON CTE.SN = CTE2.SN
Yeah, it's ugly but, hey, it did the job! :)