SSRS report parameter left blank to select all

Question

Hello,
Before posting this question I have looked at related topics and couldn't find a clear answer!
Question: Is there a workaround for a parameter to select all if blank?
I have a report that has a multivalue parameter, my user is asking if there is a way to have an empty parameter box that will default to selet all, so if the user does not fill parameter and clicks on view report it should work.
I have tried:
SELECT Item FROM ItemTable
UNION ALL
SELECT '' AS Expr1 ORDER
BY Item
Then checked Allow Blank Value ''
and checked Allow Null Values
and did the change in my query. The problem here is that the parameter will have null check box which the user does not want see?
Thanks

Answer 1

Hi There
Thanks for yourposting. I think you do not need to click on checkbox allow null value, just check allow blank value and change in your dataset query like this.
Please change the query but the synxtax might look like this
if @commenttype=''
select * from Comment_Type
else
select * from Comment_Type
where
Comment_Type=@commenttype
if @commenttype=''
select * from Comment_Type
else
select * from Comment_Type
where
Comment_Type=@commenttype
By default your parameter is blank and you display all records, but when user type something it will filter the datset based on the user input
I am putting some screenshot for your help.
If you have any questions pelase let me know
Many Thanks
Syed Qazafi Anjum
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