Question

It happends that in EF you must use ICollection for your properties,

eg. public virtual ICollection<Question> Questions { get; set; }

But I wan’t to use LINQ on that list, which is not possible in ICollection.
Should I cast it to IQueryable? How? or what is the standard way to achieve this?

Answer 1

Ryan is correct in the comments.

You need to ensure that you reference the Linq namespace.

using System.Linq;