Adding Columns heading to report if no data in a given period - tsql

Question

I have a dataset for each record it has a CompanyID, RevenueMonth, RevenueYear, Revenue
When I create the report, I am grouping each CompanyID and showing their monthly revenue for a given year.
But in a given year, not all companies have any revenues for a particular month.
Example:
A sample record would look like:
CompanyID, RevenueMonth, RevenueYear, Revenue
1,05,2013,5.00
1,08,2013,6.00
1,03,2013,3.00
End Result, I would like my report to look like this with CompanyID 1.
Company ID|01|02|03|04|05|06|07|08|09|10|11|12
1 0.00|0.00|3.00|0.00|5.00|0.00|0.00|6.00|0.00|0.00|0.00|0.00
In my current Report, it will only fill column headings with March (03), May (05) and August (08).
Company ID|03|05|08
1 3.00|5.00|6.00
How do I get my Report to add the missing months for the year?
I hope my questions is clear.

Answer 1

Database level
Since you're only returning a year at a time, you can create a calendar table and add this to your result set:
Keeping it as simple as possible, with the date table coming from a CTE:
with months as -- get required year/months
(
select RevenueYear = 2013
, RevenueMonth = 1
union all
select RevenueYear = 2013
, RevenueMonth = RevenueMonth + 1
from months
where RevenueMonth < 12
)
select CompanyID = coalesce(r.CompanyID, c.companyID)
, RevenueMonth = coalesce(r.RevenueMonth, m.RevenueMonth)
, RevenueYear = coalesce(r.RevenueYear, m.RevenueYear)
, Revenue = isnull(r.Revenue, 0.0)
from months m
cross join (select distinct CompanyID from records) c -- make sure all companies included
left join records r on m.RevenueYear = r.RevenueYear
and m.RevenueMonth = r.RevenueMonth
SQL Fiddle with demo.
This will return a year/month for each company in the result set.
In the long run it would be better to move from a CTE to a permanent calendar table in the database.
You can then implement this in the report using a matrix style tablix.
Report level
If you'd prefer to do this at the report level, you can set up a table-style tablix with 12 permanent columns, one for each month, then populate the month revenue cells with expressions like:
=Sum(IIf(Fields!RevenueMonth.Value = 2, Fields!Revenue.Value, Nothing)
For the February column.
This would work with your existing dataset without any database code changes.