You can modify your code to the below code:-
Report level you need to check null value box,when you don't want to pass the values.
when you don't pass the value it will take null value and in SQl null value will be passed and it will not use the where condition .So that all values will be fetched.
Select Project.Status, Project.Client, Project.StartDate
From Project
Where Project.Status IN case (when @parmStatus is not null then @parmStatus
when @parmStatus is null then Project.Status
end )
AND Project.StartDate IN case ( when (@parmStartDate) is not null then (@parmStartDate)
when (@parmStartDate) is null then Project.StartDate
end)
Order By Project.Status