Displaying the number of valid results for a range of dates - sql

Question

I currently have a table with a creation date and a expiry date. I currently have a sql command to get the number of valid items for a given date.
select
count(id) ,CONVERT(date, getdate())
from
table
where
createDate < getdate() and expDate > getdate()
This returns the count and current date.
Is it possible to wrote a sql query that will return the result for a range of dates, say I if wanted to plot the number of valid items over a range of 15 days?
Thanks!

Answer 1

Try this:
create table #datelist (ValidDateCheck date, ValidResults int)
declare #startdate date = '1/1/2015'
declare #enddate date = '2/1/2015'
declare #interval int = 1 --Use 1 if you want every day between your dates, use 2 if you want every other day, etc.
declare #datecounter date = #startdate
declare #count int
while #datecounter <= #enddate
begin
set #count =
(select count(*)
from Table
where CrtDt <= #datecounter and ExpDt > #datecounter)
insert into #datelist values (#datecounter, #count)
set #datecounter = dateadd(dd, #interval, #datecounter)
end
select * from #datelist order by 1
It loops through all the dates in your range, counting valid results for each one.

Answer 2

Check this,
DECLARE #StartDate DATETIME,
#EndDate DATETIME;
SELECT #StartDate = '20110501'
,#EndDate = '20110801';
SELECT
DATEADD(d, x.number, #StartDate) AS MonthName1
,
x.number
FROM master.dbo.spt_values x
WHERE x.type = 'P'
AND x.number <= DATEDIFF(MONTH, #StartDate, #EndDate);
The above query give the list of dates between 2 dates.
As per your table and question, check this also.
declare #table table(id int,frdt datetime, todt datetime)
insert into #table values (1,GETDATE()-20, GETDATE()-19)
,(2,GETDATE()-9, GETDATE()-8)
,(3,GETDATE()+20, GETDATE()+18)
,(4,GETDATE(), GETDATE()-1)
,(5,GETDATE()-20, GETDATE())
,(6,GETDATE()-10, GETDATE()+10 )
select * from #table
declare #frdt datetime = null , #todt datetime = getdate()-10
select #frdt, #todt,* from #table
where
(#frdt is null or #frdt between frdt and todt)
and
(#todt is null or #todt between frdt and todt)
select #frdt = GETDATE()-15 , #todt = GETDATE()
select #frdt, #todt,* from #table
where
(#frdt is null or #frdt between frdt and todt)
and
(#todt is null or #todt between frdt and todt)