How do I allow a drop-down list parameter in SSRS to have a default value of "-- All -- "?

Question

I have a drop-down list that gets populated based on a stored-procedure - that parts works fine.

It gets populated dynamically, based on whatever the "Survey ID" is

But I don't want it to say <Select a Value> , rather it should say " -- All -- " , because that is how the report works.

So far I tried to create a dummy-dataset that returns Null and the label of "all" but it didn't work. Maybe I did that wrong? I used this:

select distinct  Name, ID  from LK_TargetTypes
where Name like '%pizza'
union select '-- All --', null ;

So LK_TargetTypes is some irrelevant table. I want to merge that with the other DDL-values.

Here's another picture:

Any tips appreciated thanks.

Answer 1

I agree with Chris's answer however I would add that sometimes you want to add defaults to a multi value that are not all and not a single choice either. Generally I set two datasets up , each in a table variable for reporting. Similar to this:

'AvailableValues' Data set could be:

declare @Table Table ( personID int identity, person varchar(8));

insert into @Table values ('Brett'),('John'),('Peter');

select *
from @Table

'DefaultValues' Data set could be:

declare @Table Table ( personID int identity, person varchar(8));

insert into @Table values ('Brett'),('John');

select *
from @Table

If I set up a parameter and bind 'Available' values to a 'get values from a query' and choose my available dataset it has the first set. If I then choose 'Default' values and choose 'get values from a query' and choose the default I can select a subset as the default. The only issue is you must ensure your datasources in the second is a legitimate subset of the first.

You may also choose your Default from set one to get a list of all as well to choose all the values you specified.