Using Common Table Expressions with EntityFramework 5 - sql

Question

I am using EF5 Code First and I have a standard Tree type structure which is a bunch of nested Folders. Some folders have Devices inside them. What I want to do is be able to select a folder and find all devices within that folder and its child folders.
After some digging it seems I need use Common Table Expressions in order to generate the data I need. Unfortunately I am really struggling with how to do this.
public class Folder
{
public virtual ICollection<Folder> Children { get; set; }
public virtual ICollection<Device> Devices { get; set; }
}
public class Device
{
public virtual ICollection<Folder> PresentInFolders { get; set; }
}
I have attempted to add a GetDevicesForFolderRecursively function based on the work on this MSDN article. The query is incomplete as folder.FolderId equals device.FolderID wont work in my situation because a device can be in more than one folder so it has a list of folders it's in.
public IQueryable<Device> GetDevicesForFolderRecursively(int folderID)
{
return from folder in this.FlatFolders
join device in this.Devices on folder.FolderId equals device.FolderID
where folder.FolderId == folderID
select device;
}
Once this is out the way, I also dont know how accurately construct the CTE. The CTE that the MSDN article creates looks like so but I dont know how to modify it for my needs and how this would work recursively?
context.Database.ExecuteSqlCommand(#"CREATE VIEW [dbo].[ManagerEmployees]
AS
WITH cte ( ManagerEmployeeID, EmployeeID )
AS ( SELECT EmployeeID ,
EmployeeID
FROM dbo.Employees
UNION ALL
SELECT e.EmployeeID ,
cte.EmployeeID
FROM cte
INNER JOIN dbo.Employees AS e ON e.ReportsToEmployeeID = cte.ManagerEmployeeID
)
SELECT ISNULL(EmployeeID, 0) AS ManagerEmployeeID ,
ISNULL(ManagerEmployeeID, 0) AS EmployeeID
FROM cte");
Update
I have managed to get the CTE query to this state but still doesnt quite work. It doesnt understand AS ( SELECT FolderId , [EstateManagerService].dbo.Devices.DeviceSerial and im not sure what values are meant to be in there?
CREATE VIEW [dbo].[ManagerEmployees]
AS
WITH cte ( FolderID, DeviceID )
AS ( SELECT FolderId ,
[EstateManagerService].dbo.Devices.DeviceSerial
FROM [EstateManagerService].dbo.Folders
UNION ALL
SELECT e.Folder_FolderId,
cte.FolderID
FROM cte
INNER JOIN [EstateManagerService].dbo.FolderDevices AS e ON e.Folder_FolderId = cte.FolderID
)
SELECT ISNULL(DeviceID, 0) AS FolderID ,
ISNULL(FolderID, 0) AS DeviceID
FROM cte