Effective SQL Query to find a given month is in between two dates

Question

I have two dates in my subscription table ( start_date and end_date ). I want to find out if the user is subscribed in the specified month or not? For ex: start_date=11/20/2011 and end_date=03/10/2012 . I want to know all users who are subscribed in the month of Feb-2012 (02/2012) .

Thank you.

Answer 1

Given you pass in 201202 as the month of interest as a string.

Declare @StartOfMonth DateTime
Declare @EndOfMonth DateTime

Set @StartOfMonth = Convert(DateTime,@MyMonth + '01')
Set @EndOfMonth = DateSubtract(day, 1,DateAdd(month, 1, @StartOfMonth))

The it depends on whether you are interested in those subscribed for the whole month or any part of the month.

This will get you those for the whole month

Select * From Subscriptions Where
StartDate <= @StartOfMonth and EndDate >= @EndOfMonth

Or this will get you those for any part of the month

Select * From Subsciptions Where
(@StartOfMonth Between StartDate and EndDate)
Or
(@EndOfMonth Between StartDate and EndDate)

Well something like that anyway.

Answer 2

Something like this?

DECLARE @subscriptionStart datetime;
DECLARE @subscriptionEnd datetime;
DECLARE @monthStart datetime;
DECLARE @monthEnd datetime;
SET @subscriptionStart = '20111120';
SET @subscriptionEnd = '20120310';
SET @monthStart = '20120201';
SET @monthEnd = (dateadd(day,-1* day(dateadd(month,1,@monthStart)),dateadd(month,1,@monthStart)));

SELECT CASE   
        WHEN @subscriptionStart <= @monthStart 
        AND  @subscriptionEnd   >= @monthEnd 
        THEN 'month between dates' 
        ELSE 'month not between dates' END AS result

Answer 3

Not sure if I understand, because other answers are "so" complicated, but as long as you only need to know if sbdy is subscribed within a month I would do this in a simple way:

SELECT
    *
FROM 
    your_table
WHERE
    CONVERT(datetime,'2012-02-01')
        between DATEADD(month, DATEDIFF(month, 0, start_date), 0) 
            and DATEADD(month, DATEDIFF(month, 0, end_date), 0)

Just remember to put a first day of month within CONVERT function.

Answer 4

Try this

SET @SpecifiedDate = '2012/02/01'

SELECT * FROM myTable WHERE Start_Date >= @SpecifiedDate

OR

WHERE Month(@SpecifiedDate) = MONTH(Start_Date) AND YEAR(@SpecifiedDate) = YEAR(Start_Date)

You can use this

WHERE Month(@SpecifiedDate) >= MONTH(Start_Date) AND Month(@SpecifiedDate) <= MONTH(End_Date)

But I prefer using the the full date (with the year, month and 01 as day). Thus I won't worry about the year since SQL will handle the filtering

WHERE @SpecifiedDate >= Start_Date AND @SpecifiedDate <= End_Date