I have a data set created by a lengthy union of half a dozen tables.
I want the user to be able to filter this data set on multiple or all districts.
I created a multi-select report parameter which allows me to select several districts. This works fine.
I would like to add the default value 'All' so that the filter actually doesn't filter.
Is there a way to do this?
Modifying the query text is too cumbersome because I would have to parse every table union.