var r = Enumerable.Range(1, 10).Select(i => i.ToString());
        var list = new EntityCollection<BookEntity>();
        list.AddRange(r.Select(a => new BookEntity{Name = a}));

        r.Count(); returns 0

but if I use List<BookEntity>() instead then r.Count(); return 10

any idea why?

BR PoKrec

Why don't you check on list.Count?

Walaa wrote:

Why don't you check on list.Count?

list will have all 10 new entities, but I wanted to use r later with other query

I can't reproduce it. (V.S.2010, .NET 4.0) I used the following:

            var r = Enumerable.Range(1, 10).Select(i => i.ToString());
            var list = new EntityCollection<CustomerEntity>();
            list.AddRange(r.Select(a => new CustomerEntity { ContactName = a }));

            var count = r.Count(); // returns 10;

it was my mistake related to ling and and foreach thx