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

You need to check if your values are null before doing the query, and if they are, don't do the extra condition.

List lstDatExp = 
    (from l in ctx.dExp.Include("datLab")
     where 
         (values == null || values.Contains(l.datL.Lab_ID)) &&
         (reportingPeriod == null || l.reportingPeriod == reportingPeriod)
     select l).ToList();

This way if values or reportingPeriod are null they are essentially optional.