sql server - How to make SSRS filter selection optional? -

i'm using sql server 2005 reporting services create new report.

this report has 2 optional parameters can selected users or users can leave them blank. both dropdown selection.

the problem i'm facing is, had set both parameters allow null value, not allow blank value. when click on view report button without select filter criteria, report give me 0 records. if selected value both dropdown selection, reports give me result.

@package varchar(100) , @plant tinyiny.

i write where clause in way. please , appreciate.

where (@package ='' or package_type '%' + @package + '%') ,  (@plant null or plant_id = @plant ) 

so when no filter criteria selected, both @package , @plant null?

in where clause above, you're handling @plant null values.

you need check null @package, too, like:

where (@package null or @package ='' or package_type '%' + @package + '%') ,   (@plant null or plant_id = @plant )