Cognos - Date variables for many queries - variables

Question

I'm using Bullhorn Canvas which runs on Cognos. I'm looking for the simplest way to have query filters based on a prompt with this dropdown:
THIS WEEK
LAST WEEK
THIS MONTH
LAST MONTH
THIS QUARTER
LAST QUARTER
YEAR TO DATE
The report requires many queries with date filters. As far as I can see, I have to write filters in each query that look like this:
[StartDate] between
(case ?Dates Dropdown?
when 'THISWEEK' then _add_days(current_date, -_day_of_week(current_date, 1) + 1)
when 'LASTWEEK' then _add_days(current_date, -_day_of_week(current_date, 1) - 6)
when 'THISMONTH' then _first_of_month(current_date)
end)
and
(case ?Dates Dropdown?
when 'THISWEEK' then _add_days(current_date, -_day_of_week(current_date,1) + 7)
when 'LASTWEEK' then _add_days(current_date, -_day_of_week(current_date,1))
when 'THISMONTH' then _last_of_month(current_date)
when 'LASTMONTH' then _last_of_month(_add_months(current_date, -1))
end)
This is actually shortened. The real filter will be even bigger than this.
As far as I can see, I have to repeat this monstrous filter in every query, and I'd like to avoid that. In other programming languages, I'd create two variables, for example Date1 and Date2. I'd calculate those variables once, based on the dropdown. Then each query would simply say [StartDate] between [Date1] and [Date2].
Is there a way to do this in Cognos?

Answer 1

As a suggestion, we can use the value prompt with static values to set the ranges and then use a join to have the query (or multiple queries) filter based on that range
Step 1 create a value prompt with static values like this:
Step 2 create a query that will have the data items for the ranges like this:
Each data item has the case statement like you gave above
For example, this would be for the data item FromRange
Step 3 navigate to where you can see all of your queries. From the insertable objects, using a join you will have your query follow the from and to range like this:
The join would look like this (note towards the bottom for the operator we use >= for FROM):
and this for the range (and the <= for the TO):
Remember in the Query from the join you just need to re-add the data items you want to show in your content