use AsEnumerable with the entity like this!
public IEnumerable<dml.person> GetAll()
{
var a = (from p in dbo.Person.AsEnumerable()
join r in dbo.Role.AsEnumerable() on p.PersonRoleID equals r.RoleID
select new DML.Person {
Name = p.Name,
Role= r.Name
});
return a;
}
</dml.person>