One SQL Stored Procedure to get cut off date of two different cut off date format - tsql

Question

I have one system that read from two client databases. For the two clients, both of them have different format of cut off date:
1) Client A: Every month at 15th. Example: 15-12-2016.
2) Client B: Every first day of the month. Example: 1-1-2017.
The cut off date are stored in the table as below:
Now I need a single query to retrieve the current month's cut off date of the client. For instance, today is 15-2-2017, so the expected cut off date for both clients should be as below:
1) Client A: 15-1-2017
2) Client B: 1-2-2017
How can I accomplish this in a single Stored Procedure? For client B, I can always get the first day of the month. But this can't apply to client A since their cut off is last month's date.

Answer 1

Might be something like this you are looking for:
DECLARE #DummyClient TABLE(ID INT IDENTITY,ClientName VARCHAR(100));
DECLARE #DummyDates TABLE(ClientID INT,YourDate DATE);
INSERT INTO #DummyClient VALUES
('A'),('B');
INSERT INTO #DummyDates VALUES
(1,{d'2016-12-15'}),(2,{d'2017-01-01'});
WITH Numbers AS
( SELECT 0 AS Nr
UNION ALL SELECT 1
UNION ALL SELECT 2
UNION ALL SELECT 3
UNION ALL SELECT 4
UNION ALL SELECT 5
UNION ALL SELECT 6
UNION ALL SELECT 7
UNION ALL SELECT 9
UNION ALL SELECT 10
UNION ALL SELECT 11
UNION ALL SELECT 12
UNION ALL SELECT 13
UNION ALL SELECT 14
UNION ALL SELECT 15
UNION ALL SELECT 16
UNION ALL SELECT 17
UNION ALL SELECT 18
UNION ALL SELECT 19
UNION ALL SELECT 20
UNION ALL SELECT 21
UNION ALL SELECT 22
UNION ALL SELECT 23
UNION ALL SELECT 24
)
,ClientExt AS
(
SELECT c.*
,MIN(d.YourDate) AS MinDate
FROM #DummyClient AS c
INNER JOIN #DummyDates AS d ON c.ID=d.ClientID
GROUP BY c.ID,c.ClientName
)
SELECT ID,ClientName,D
FROM ClientExt
CROSS APPLY(SELECT DATEADD(MONTH,Numbers.Nr,MinDate)
FROM Numbers) AS RunningDate(D);
The result
ID Cl Date
1 A 2016-12-15
1 A 2017-01-15
1 A 2017-02-15
1 A 2017-03-15
1 A 2017-04-15
1 A 2017-05-15
1 A 2017-06-15
1 A 2017-07-15
1 A 2017-09-15
1 A 2017-10-15
1 A 2017-11-15
1 A 2017-12-15
1 A 2018-01-15
1 A 2018-02-15
1 A 2018-03-15
1 A 2018-04-15
1 A 2018-05-15
1 A 2018-06-15
1 A 2018-07-15
1 A 2018-08-15
1 A 2018-09-15
1 A 2018-10-15
1 A 2018-11-15
1 A 2018-12-15
2 B 2017-01-01
2 B 2017-02-01
2 B 2017-03-01
2 B 2017-04-01
2 B 2017-05-01
2 B 2017-06-01
2 B 2017-07-01
2 B 2017-08-01
2 B 2017-10-01
2 B 2017-11-01
2 B 2017-12-01
2 B 2018-01-01
2 B 2018-02-01
2 B 2018-03-01
2 B 2018-04-01
2 B 2018-05-01
2 B 2018-06-01
2 B 2018-07-01
2 B 2018-08-01
2 B 2018-09-01
2 B 2018-10-01
2 B 2018-11-01
2 B 2018-12-01
2 B 2019-01-01