get last 3 month on year in sql server - sql

Question

I want to get last 3 months name from current month. For example current month is December. So, I want get like this October, November and December.
This is my query:
SELECT CONVERT(CHAR, DATENAME(MONTH, IssueDate)) AS MonthName, ItemId
FROM dbo.Issue AS Issue
GROUP BY CONVERT(CHAR, DATENAME(MONTH, IssueDate)), ItemId
HAVING (ItemId = 427)
This returns:
But, my need is:
N.B. When December month close and January month open then October auto excluded as like (November, December and January)
this link is my Database only 2 table (size-243 KB with Zip) on the google drive https://goo.gl/S4m0R5

Answer 1

Add a date diff in a where clause to filter to the last 3 months, and then order by the month number at the end:
SELECT CONVERT(CHAR, DATENAME(MONTH, [IssueDate])) AS MonthName, ItemId
FROM [dbo].[Issue] AS Issue
WHERE datediff(m, [IssueDate], getdate()) between 0 and 2
GROUP BY CONVERT(CHAR, DATENAME(MONTH, [IssueDate])), ItemId, MONTH(IssueDate)
HAVING (ItemId= 427)
order by MONTH(IssueDate);

Answer 2

You can use DATEADD function:
WHERE IssueDate >= dateadd( month, -2, dateadd( day, -datepart( day, getdate() ) + 1, cast( getdate() as date ) ) )
That will give you IssueDate >= '2015-10-01' given today.
That will also work with index you have on IssueDate, if you start doing something like DATEADD / DATEDIFF etc. on IssueDate then the index can only be scanned end-to-end because it needs to processs all rows in the table so renders the index significantly less effective.

Answer 3

DECLARE #t TABLE
(
IssueDate DATETIME,
ItemId INT
)
INSERT INTO #t (IssueDate, ItemId)
VALUES
('20160105', 427),
('20151212', 427),
('20151213', 427),
('20151110', 427),
('20151001', 427),
('20150905', 427)
SELECT DATENAME(MONTH, dt)
FROM (
SELECT DISTINCT TOP(3) DATEADD(MONTH, DATEDIFF(MONTH, 0, IssueDate), 0) AS dt
FROM #t
WHERE ItemId = 427
ORDER BY dt DESC
) t
results -
------------------------------
January
December
November

Answer 4

You can use a recursive CTE to get month names for the last 12 months and then limit it to the last 3 month names in the second part of the query:
;WITH months(MonthNumber) AS
(
SELECT 0
UNION ALL
SELECT MonthNumber+1
FROM months
WHERE MonthNumber < 12
)
SELECT DATENAME(MONTH,DATEADD(MONTH,-MonthNumber,GETDATE())) AS [month]
FROM dbo.Issue AS Issue
CROSS JOIN months m
WHERE m.MonthNumber <3
GROUP BY DATENAME(MONTH,DATEADD(MONTH,-MonthNumber,GETDATE())) , ItemId
HAVING (ItemId = 427)