Only do Where condition if a value is passed in

Question

I have the following LINQ statement that does on where on the date and a LabID.

I\'m passing in a list of LABS and a date, however

Answer 1

What we do is something like (l.reportingPeriod == reportingPeriod || reportingPeriod == null) So you check to see if the parameter is its default meaning it hasnt been used or if there is something there check it against the database.