Crystal Reports Parameters prompts

Message

Hi,

I’m trying to setup multiple parameter prompts within my SQL statement so the users can choose both the values or choose individual values.
So far it displays the prompts properly but only works if I select and populate both prompts at once and not either or.
The SQL statement for the parameters is as followed, with two parameters setup in the parameter list called Project and Project2.
("project_group"."project_group_id" = {?Project} or "project_group"."project_group_id" = {?Project2})
Any ideas on how to select either / or to produce the report?
I am trying to set up parameters within the SQL statement because it is faster to gather the results then setting up parameters within Crystal.

Thanks.