asp.net mvc - Only parameterless constructors and initializers are supported in LINQ to Entities? -

i have productviewmodel converts dto (product) @ runtime.

public class productviewmodel : iviewmodel {      public productviewmodel() {         categories = new list<categoryviewmodel>();     }      #region dto helpers      public productviewmodel(product p) {         this.id = p.id;         this.name = p.name;         this.price = p.price;         categories = new list<categoryviewmodel>();     }      #endregion       public int id { get; set; }     public string name { get; set; }     public decimal price { get; set; }     public ienumerable<categoryviewmodel> categories { get; set; } } 

i've used code linq2sql before , it's worked, entity framework doesn't:

        var products = (from p in db.getall()                         select new productviewmodel(p)); 

i error:

only parameterless constructors , initializers supported in linq entities 

can explain/fix this?

var products = (from p in db.getall()                select new productviewmodel{                    id = p.id,                    ....                });