How to declare dates in SQL multiple value - sql-server

Question

I am trying to create my SQL syntax so that we can have versatile input. I figured out how to do it for one set date and it worked.
my syn is:
DECLARE #MyDay AS VARCHAR(50);
DECLARE #NextDay AS VARCHAR(50);
SET #MyDay = '8/30/2016';
SET #NextDay = DATEADD(d, 1, #MyDay);
However, I'm stuck with how to do it for multiple dates. Ideally I would like to put in a range of date, and from that it will scan the records, i.e. set range between oct 1st and oct 5th.
I'm using SQL Server Management Studio 2008

Answer 1

If you just want a series of days and next days between 8/30/16 and 9/5/16, you can use a derive table method like below.
declare #n int;
declare #StartDate datetime, #EndDate datetime;
set #n = 5;
set #StartDate = '20160830';
set #EndDate = dateadd(day, #n, #StartDate);
select cast(dateadd(day, number, #StartDate) as date) as MyDate,
cast(dateadd(day, number + 1, #StartDate) as date) as MyNextDate
from
(select distinct number from master.dbo.spt_values
where name is null
) n
where dateadd(day, number, #StartDate) < #EndDate;
Alternately you can use a temp table, table variable to store your dates, or a cte as well.
A recursive cte imlementation example is given below. Please note you would want to set MAXRECURSION option if you have a long date range as default for max recursion is 100.
declare #n int;
declare #StartDate datetime, #EndDate datetime;
set #n = 5;
set #StartDate = '20160830';
set #EndDate = dateadd(day, #n, #StartDate);
;with DateSeq as
(
select cast(#StartDate as date) as MyDate
union all
select dateadd(day , 1, MyDate) AS MyDate
from DateSeq where dateadd (day, 1, MyDate) < #EndDate
)
select MyDate, dateadd(day , 1, MyDate) AS NextDate
from DateSeq;
A temp table implementation example is as below.
declare #MyDateRange table(MyDate date);
Insert into #MyDateRange values('8/30/2016')
Insert into #MyDateRange values('9/1/2016')
Insert into #MyDateRange values('9/2/2016')
Insert into #MyDateRange values('9/3/2016')
Insert into #MyDateRange values('9/4/2016')
select MyDate, dateadd(day, 1, MyDate) as NextDate from #MyDateRange