Question

I want to do something like that;

Context.Users.Include("Addresses", a => a.IsRowDeleted == false).FirstOrDefault(u => u.UserId == 5);

I mean; I want to filter included entities but not always, its also have to be optional.

What is the best solution for this? Please help me,

Answer 1

You cannot filter eager loaded data in EF. Include operation doesn’t support filtering or sorting.

You must use either projection to custom type (or anonymous type):

var query = from u in context.Users
            where u.UserId == 5
            select new UserFiltered 
                { 
                    User = u,
                    Addresses = u.Addresses.Where(a => !a.IsRowDeleted)
                };
UserFiltered u = query.FirstOrDefault();

Or you must devide your query into two separated queries and use explicit loading:

context.ContextOptions.LazyLoadingEnabled = false;
var user = context.Users.FirstOrDefault(u => u.UserId == 5);
((EntityCollection<Address>)user.Addresses)
     .CreateSourceQuery()
     .Where(a => !a.IsRowDeleted)
     .Execute();               

Or you can simply use two queries:

var user = context.Users.FirstOrDefault(u => u.UserId == 5);
var addresses = context.Addresses.Where(a => a.User.UserId == 5 && !a.IsRowDeleted).ToList();