Linq optional parameters

Question

I have a linq query. I have a bunch of parameters from a form I collect where I need to filter based of fields the user is searching for.

IQueyable

        

Answer 1

If the query doesn't include a particular field, you don't need to include it as part of the where clause at all:

IQueyable user = from user in edmxObject.Users;

if (model.FirstName != null) 
    users = users.Where(user => user.FirstName.Contains(model.FirstName)

if (/* age is searched for */) 
    users = users.Where(user => user.Age == model.Age);

You can conditionally nest predicates this way to ensure you have only the conditions you really need.