Check if date falls within Month and Year range - sql-server

Question

If a user selects a range such as:
Start: November 2016
End: September 2017,
I want to include all results that fall within the range of 2016-11-01 to 2017-09-30.
I tried concatenating together the year, month, and day, however the issue comes that not all months have the same last day. While I know all months start on day 01, a month's end day can be 28, 29, 30, or 31.
Is there a way to do this without constructing the date? SqlServer 2008 doesn't have the EOMONTH function, and I feel like anything more complex than that is not the right solution. I would like to avoid this:
WHERE
DateCol >= '2016' + '-' + '11' + '-01' AND
DateCol <= '2017' + '-' + '09' + '-30'

Answer 1

It really seems to me that the easiest and best answer is to go from the first of the beginning month to the first of the month after the ending month, and make the second comparison not inclusive.
In other words, instead of this:
WHERE
DateCol >= '2016' + '-' + '11' + '-01' AND
DateCol <= '2017' + '-' + '09' + '-30'
simply this:
WHERE
DateCol >= '2016' + '-' + '11' + '-01' AND
DateCol < '2017' + '-' + '10' + '-01'

Answer 2

There is a faster way to do so :
DECLARE #minDate DATE
DECLARE #maxDate DATE
SET #minDate = XXXXX
SET #maxDate = YYYYY
-- Get the first day of the month minDate.
SET #minDate = CONVERT(datetime,CONVERT(varchar(6),#minDate,112)+'01',112)
-- Get the last day of the month minDate.
SET #maxDate = CONVERT(datetime,CONVERT(varchar(6),#maxDate,112)+'01',112)
SET #maxDate = DATEADD(day, -1, DATEADD(month, 1, #maxDate))
SELECT * FROM myTABLE WHERE DateCol >= #minDate AND DateCol <= #maxDate
Or :
SELECT * FROM myTABLE
WHERE DateCol >= CONVERT(datetime,CONVERT(varchar(6),XXXXX,112)+'01',112)
AND DateCol <= DATEADD(day, -1, DATEADD(month, 1, CONVERT(datetime,CONVERT(varchar(6),YYYYY,112)+'01',112)))
Use syntax like CONVERT(datetime,'20170930',112) or CONVERT(datetime,'09-30-2017',110) for XXXXX and YYYYY rather than '2017-09-30' that use SQL Server implicit convertion from char to datetime (rely on the server configuration : can be hazardous!!!)).
Using this syntax is faster because #minDate and #maxDate do not need any evaluation. So that indexes can be used directly...
Otherwise a scalar function that will simulate the eomonth() behaviour could be usefull...

Answer 3

You could use following select statement to get last date of any month (and any year) by passing a field or date to it:
DECLARE #dtDate DATE
SET #dtDate = '09/25/2016'
SELECT CAST(DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,#dtDate)+1,0)) AS DATE) AS LastDay_AnyMonth
Please provide some example data and desired result and I will update my answer further.

Answer 4

Here you go:
DECLARE #YourTable TABLE (YourData DATE);
INSERT INTO #YourTable VALUES
('2016-11-01'),
('2016-09-05'),
('2017-03-03'),
('2017-11-11'),
('2017-12-14'),
('2017-09-30');
WITH CTE AS (
SELECT YourData
FROM #YourTable
WHERE YEAR(YourData) =2016 AND MONTH (YourData) >= 11
)
SELECT YourData
FROM #YourTable
WHERE YEAR(YourData) =2017 AND MONTH (YourData) <= 9
UNION ALL
SELECT YourData
FROM CTE;
There is no need to know the end of the month (28 or 30 or 31).

Answer 5

For 2008, you can simply convert the string
Example
Select Date1=convert(date,'November 2016')
,Date2=dateadd(DAY,-1,dateadd(MONTH,1,convert(date,'September 2017')))
Returns
Date1 Date2
2016-11-01 2017-09-30
So the WHERE would be somthing like this
...
Where DateCol between convert(date,'November 2016')
and dateadd(DAY,-1,dateadd(MONTH,1,convert(date,'September 2017')))

Answer 6

A useful construct for performing date-based operations is to make use of a Date Dimension table. You are creating a lookup table that is populated with a lot of information about dates over a large span of time. You can then query the table based on the information that you do have. The table is small enough so that it does not impose significant performance concerns.
In your particular case, you have the month and year. You would plug that into the date dimension table to get the first of the month from the beginning month and the last of the month from the ending month. You now have a time range to search over without any complex logic or calculations on the fly.
Aaron Bertrand explains it in depth here: https://www.mssqltips.com/sqlservertip/4054/creating-a-date-dimension-or-calendar-table-in-sql-server/