RE: Fiscal Week in TSQL – SQLServerCentral

SSC Guru

Points: 186127

July 29, 2013 at 6:09 am

Something to get the ball rolling. There are folks here who love date arithmetic and will come up with something quicker and more elegant, but you get the general idea;

;WITH MySampleData AS (

SELECT MyDate = '20120331' UNION ALL

SELECT MyDate = '20120401' UNION ALL

SELECT MyDate = '20120801' UNION ALL

SELECT MyDate = '20121231' UNION ALL

SELECT MyDate = '20130331' UNION ALL

SELECT MyDate = '20130401' UNION ALL

SELECT MyDate = '20130901' UNION ALL

SELECT MyDate = '20131231' UNION ALL

SELECT MyDate = '20140331' UNION ALL

SELECT MyDate = '20140401' UNION ALL

SELECT MyDate = GETDATE())

SELECT MyDate, FiscalWeek

FROM MySampleData

CROSS APPLY (SELECT OffsetYear = CASE WHEN MONTH(MyDate) < 4 THEN YEAR(MyDate)-1 ELSE YEAR(MyDate) END) x

CROSS APPLY (SELECT FiscalWeek = 1+DATEDIFF(WK,DATEADD(MM,3,CAST(OffsetYear AS CHAR(4))),MyDate)) y

^{“Write the query the simplest way. If through testing it becomes clear that the performance is inadequate, consider alternative query forms.” - Gail Shaw}

For fast, accurate and documented assistance in answering your questions, please read this article.
Understanding and using APPLY, (I) and (II) Paul White
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