Generation of all days in a month in SSRS - reporting-services

Question

I am designing a report where I need to display all days in a month(ex: 1- 30 for month of april) and display information associated to it. But my report displays only dates that have data associated to it and ignores all other days. Is there any way to display all the days in the report irrespective of the data?

Answer 1

As Wil hints at in his comment, it is easiest to generate these days in your dataset/query. This is a perfect place to use a CTE (Common Table Expression). These generate a table that you can use in your query, and they support recursion, so it is easy to generate a table with as many days as you want.
A Google of "cte days in a month" gave me this link as one of the top results: http://smehrozalam.wordpress.com/2009/06/09/t-sql-using-common-table-expressions-cte-to-generate-sequences/
Please leave a comment if this doesn't make sense.
OK, here's a sample using a CTE with days of the current month.
WITH DaysOfMonthCTE
AS ( SELECT DATEADD(month, DATEDIFF(MONTH, 0, GETDATE()), 0) AS StartDate ,
DATEADD(month, DATEDIFF(MONTH, 0, GETDATE()), 1) AS EndDate
UNION ALL
SELECT DATEADD(day, 1, StartDate) ,
DATEADD(DAY, 1, EndDate)
FROM DaysOfMonthCTE
WHERE EndDate < DATEADD(month,
DATEDIFF(MONTH, 0, GETDATE()) + 1, 0)
)
SELECT Student.Name ,
DaysOfMonthCTE.StartDate ,
AVG(Scores.TestScore) AS AverageScore
FROM myStudentsTable AS student
INNER JOIN myScoresTable scores
ON student.ID = scores.StudentID
RIGHT OUTER JOIN DaysOfMonthCTE
ON scores.TestDate >= DaysOfMonthCTE.StartDate
AND scores.TestDate < DaysOfMonthCTE.EndDate
GROUP BY Student.NAME ,
DaysOfMonthCTE.StartDate

Answer 2

Answer by #JamieF is spot-on but I was looking for a more general purpose date generator where I can get a list of dates between a start date and end date. The OP asked for all the days in a month, so this answer is not really for the OP. I added here in the event someone (like me) is looking for how to generate sequential data in a range on the fly in SSRS.
I merely added the following as the basis for my query in a dataset, and used two parameters - #StartDate and #EndDate.
;with DateGenerator
as (
select
CONVERT(datetime, #StartDate) GeneratedDate
union all select
DATEADD(day, 1, GeneratedDate)
from
DateGenerator
where GeneratedDate < #EndDate
)
select
GeneratedDate
from
DateGenerator
option (maxrecursion 32767)
Beware - limit is range of 32767 days. If the range is larger than that this solution will implode.
To use, merely join your query to the pseudotable DateGenerator (line above 'option' statement)