Get dates for last 30 days dynamically in SQL - sql

Question

I have below SQL which gives me count of files received in particular country according to date. But here dates are hard coded. I want them dynamically. I want it in such a way that whenever I run this query, I get result for last 30 days. Below is the SQL:
with t (Country ,Date,total)
as
(
select b.country as Market, CAST(a.ProcessDate AS Date) AS DATE, count(a.ProcessDate) AS total from Log a LEFT JOIN File b ON a.FileID = b.FileID where a.ProcessDate BETWEEN '2022-11-01' AND '2022-11-07' GROUP BY b.country, CAST(a.ProcessDate AS DATE)
)
Select
*
from
(
Select
Date,
Total,
Country
from t
) x
Pivot(
sum(total)
for Date in (
[2022-11-01],
[2022-11-02],
[2022-11-03],
[2022-11-04]
)
) as pivottable
Below is Result of the query with dummy data:
Country
2022-11-01
2022-11-02
2022-11-03
2022-11-04
Brazil
2
1
Chile
1
1
Switzerland
1
Below is the structure of MasterFile and FileProcessLog with dummy data:
MasterFile:
FileID
Country
1
Brazil
2
Brazil
3
Chile
4
Chile
5
Switzerland
FileProcessLog:
FileID
ProcessDate
1
2022-11-01T15:31:53.0000000
2
2022-11-01T15:32:28.0000000
3
2022-11-02T15:33:34.0000000
4
2022-11-03T15:33:34.0000000
5
2022-11-04T15:37:10.0000000

Answer 1

Create function as below to return last 30 day dates:
CREATE FUNCTION [dbo].[RETURNDATE]()
RETURNS
#ParsedList table
(
DATEINFO DATE
)
AS
BEGIN
DECLARE #Counter Int
SET #Counter=1
WHILE ( #Counter <= 30)
BEGIN
--PRINT 'The counter value is = ' + CONVERT(VARCHAR,Convert(Date,DATEADD(DAY, -(#Counter), getdate())))
INSERT INTO #ParsedList (DATEINFO)
VALUES (CONVERT(VARCHAR,Convert(Date,DATEADD(DAY, -(#Counter), getdate()))))
SET #Counter = #Counter + 1
END
RETURN
END
now use inside your code as below:
DECLARE #cols AS NVARCHAR(MAX),
#query AS NVARCHAR(MAX)
select #cols = STUFF((SELECT distinct ',' + QUOTENAME([DateInfo])
from [DBO].RETURNDATE()
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
set #query = 'WITH t (Country ,Date,total) AS (
SELECT b.country as Market,
CAST(a.ProcessDate AS Date) AS DATE,
COUNT(a.ProcessDate) AS total
FROM [dbo].[FileProcessLog] a
LEFT JOIN [dbo].[MasterFile] b ON a.FileID = b.FileID where a.ProcessDate BETWEEN ''2022-11-01'' AND ''2022-11-07''
GROUP BY b.country, CAST(a.ProcessDate AS DATE)
)
SELECT * FROM (SELECT Date,Total,Country from t) x
PIVOT(SUM(total)
FOR Date IN ('
+ #cols +
')
) as PIVOTTABLE
'
execute(#query)
I think your full answer is ready now. Happy Coding.