SQL function for last 12 months - sql

Question

I am looking for a SQL-function that gives the last 12 months with Start Date and End Date. Say you pick 10.Dec, it will give a result in:
- StartDate -- EndDate
- 2013-11-01 - 2013-11-30
- 2013-10-01 - 2013-10-31
- 2013-09-01 - 2013-09-30
and so it goes for the last 12 months.
I tried modifying an old function we had, but I got totally off and confused in the end.
ALTER FUNCTION [dbo].[Last12Months](#Date date) RETURNS TABLE
AS
Return
(
with cte as (
SELECT DATEADD(mm, DATEDIFF(mm, 01, #Date), 01) AS Start,
DATEADD(mm, DATEDIFF(mm, -12, #Date), -12) AS EndDate
union all
select Start - 1, EndDate - 1 from cte
where Start >= #Date )
select CAST(Start as DATE) StartDate, CAST(EndDate as DATE) EndDate from cte)
Runned it like this:
select * from dbo.Last12Months ('2013-12-10')
and got:
- StartDate - EndDate
- 2013-12-02 - 2013-12-20
Anyone know what to do?

Answer 1

Please try using CTE:
ALTER FUNCTION [dbo].[Last12Months]
(
#Date datetime
) RETURNS #tbl TABLE (Start datetime, EndDate datetime)
AS
BEGIN
WITH T AS(
SELECT
DATEADD(month, DATEDIFF(month, 0, #Date), 0) AS Start,
DATEADD(d, -DAY(DATEADD(m,1,#date)),DATEADD(m,1,#date)) AS EndDate,
12 Cnt
UNION ALL
SELECT
DATEADD(month, -1, Start),
DATEADD(d, -DAY(DATEADD(m,1,Start-1)),DATEADD(m,1,Start-1)),
Cnt-1
FROM
T
WHERE
Cnt-1>0
)
INSERT INTO #tbl
(Start, EndDate)
SELECT
Start, EndDate
FROM T
RETURN
END

Answer 2

This seems to do the job - whether you want to put it in a function or just wherever you need to have the data:
; With Numbers as (
select ROW_NUMBER() OVER (ORDER BY number ) as n
from master..spt_values
), Months as (
select DATEADD(month,n,'20010101') as start_date,
DATEADD(month,n,'20010131') as end_date
from Numbers
)
select * from Months
where DATEDIFF(month,start_date,GETDATE()) between 0 and 11
(Substitute any other date for GETDATE() if you want to get it based on some other date)
(On my machine, this can generate any month from January 2001 on to at least the next century - it can be adjusted if you need earlier or later dates also)

Answer 3

Damn, you've got to be quick on SO!
Good use of CTEs: i've learnt a bit answering this...
alter function Last12Months(#d date) returns table
as
return(
with cte as (
select
dateadd(month, datepart(mm,#d)-13,
dateadd(year,datepart(yyyy,#d)-1900,0)
)
as start
union all
select dateadd(mm, 1, start) from cte
where start < #d)
select start, dateadd(mm, 1, start) ends from cte
where start < #d
)
go
select * from Last12Months('2014-06-04')
Removed conversion to varchar thanks to
Date serial in SQL?
This returns 13 months: from say June last year to this June, inclusive.
To return the previous 12 months, not including the current June, change the final start<#d to
where start < dateadd(month, datepart(mm,#d)-1,
dateadd(year,datepart(yyyy,#d)-1900,0))
The end is 00:00 hours on the first day of the next month.

Answer 4

check this,
Declare #i date='2013-12-10'
;with cte as
(Select dateadd(month,datediff(month,0,#i)-1,0) StartDate
,dateadd(day,-1,dateadd(month,datediff(month,0,#i),0)) EndDate ,1 rownum
Union all
select dateadd(month,-1,StartDate),dateadd(day,-1,StartDate),rownum+1 rownum from cte where rownum<12 )
select * from cte

Answer 5

#Lebowski Below script will give you start and end date of specified calendar months from today in chronological order
DECLARE #nMonths TINYINT
SET #nMonths = 60
SELECT FORMAT(DATEADD(month, n.n - #nMonths+1+ DATEDIFF(month, 0, GETDATE()) -1 ,0), 'yyyy-MM-dd') AS MonthStartDate
, FORMAT(DATEADD(dd, -1, DATEADD(month, n.n - #nMonths+1 + DATEDIFF(month, 0, GETDATE()),0)), 'yyyy-MM-dd') AS MonthEndDate
FROM (SELECT TOP(#nMonths) n = ROW_NUMBER() OVER (ORDER BY NAME)
FROM master.dbo.syscolumns) n
Sample output
MonthStartDate MonthEndDate
2011-04-01 2011-04-30
2011-05-01 2011-05-31
2011-06-01 2011-06-30
2011-07-01 2011-07-31
2011-08-01 2011-08-31
2011-09-01 2011-09-30
2011-10-01 2011-10-31
2011-11-01 2011-11-30
2011-12-01 2011-12-31
....

Answer 6

Try this it might help you
select top 12 *
from YourTable
where dateOf between #DateFrom and #DateTo
order by dateOf desc