LINQ: adding where clause only when a value is not null

Question

I know a typical way is like this:

IQueryable query = from staff in dataContext.Staffs;
if(name1 != null)
{
     query = from staff in query where (staff.nam         


        

Answer 1

I like use the Expression e.g.

    Expression> expresionFinal = c => c.Active == true;

    if (DateBirth.HasValue)
                {
                    Expression> expresionDate = c => (EntityFunctions.TruncateTime(c.DateBirth) == DateBirth);
                    expresionFinal = PredicateBuilder.And(expresionFinal, expresionDate);
                }

IQueryable query = dataContext.Persons;
 query = query.Where(expresionFinal);