LINQ to Entities projections - asp.net-mvc-3

Question

UPDATE: I essentially want to get a list of all permissions and a list of all permissions for a given role. I then want to mark each permission in a list of SelectListItems as selected when they already belong to the Role
I have three tables:
Project 1-* Role - Permission
I am trying to create and IEnumerable using projection that has all permissions in the list but when I project to SelectItemList it identifies the Permissions that are already associated with a particular role:
public IEnumerable GetAllPermissionsPLusRole(int projectid, int roleid)
{
using (var db = new Entities())
{
var permissions = (from p in db.Permissions
select p).ToList();
var permissionsForRole = from r in db.Roles
where r.RoleId == roleid && r.PrjectProjectId == contractid
select r.Permissions.ToList();
IEnumerable<SelectListItem> selectList = from p in permissions select new SelectListItem { Text = p.PermissionName, Value = p.PermissionId.ToString()};
return selectList;
}
}
What I want to do is have a conditional Selected in the projection so when I display the list I can show the permissions already associated to the Role.
Thanks in advance.

Answer 1

If I understand it right, you've already fetched all the data, now you just need to check if given permission is in the permissionsForRole list, i.e. like that:
IEnumerable<SelectListItem> selectList = from p in permissions
select new SelectListItem
{
Text = p.PermissionName,
Value = p.PermissionId.ToString(),
Selected = permissionsForRole.Contains(p)
};