SQL Server database design: Advice on many to many relationship

I am setting up a database and am at a place where I am confusing myself on some many-to-many tables. I am looking for some advice on the best way to design this for performance and scalability.

I will lay out an example of my setup and what I am trying to do below.

I have the main object table...

Account

AccountID| AccountName
-----------------------
   1     | First Account

...and then the child objects to be given permissions to.

Page

PageID | PageName
------------------
   1   | First Page

Control

ControlID | ControlName
-----------------------
   1      | First Control

MenuItem

MenuItemID | MenuItemName
-------------------------
    1      | Menu Item 1

I have a permissions table for read/write etc...

Permission

PermissionID | PermissionName
------------------------------
    1        | CanRead
    2        | CanWrite
    3        | CanDelete

So I'm trying to tie the permission table in a many-to-many between the main objects and the child objects. I will list below what I've come up with and why I don't think it's righ开发者_如何学编程t.

One table to rule them all

PermissionAccount

AccountID | PermissionID | ControlID | MenuItemID | PageID
----------------------------------------------------------
      1   |     2        | NULL      | NULL       | NULL
      2   |   NULL       | 2         | NULL       | NULL

*this solution is just ugly. There can be many MenuItemID's assigned to a single account

One table for every object

PermissionAccountControl

AccountID | ControlID | PermissionID
------------------------------------
    1     |    1      |     1
    1     |    2      |     1

PermissionAccountMenuItem

AccountID | MenuItemID | PermissionID
-------------------------------------
    1     |     1      |     2
    1     |     2      |     1

PermissionPage

AccountID | PageID | PermissionID
---------------------------------
    1     |   1    |    3
    1     |   2    |    1

I am leaning more toward option two. Any thoughts or suggestions are appreciated.

The latter is correct

This is 4th/5th normal form when designing a database

You could also use polymorphic association

+------------+------------+----------+--------------+
| AccountID  | ObjectType | ObjectID | PermissionID |
+------------+------------+----------+--------------+
|     1      | Page       |    1     |      1       |
|     1      | MenuItem   |    1     |      2       |
+------------+------------+----------+--------------+

This method might be useful if you need to handle permissions for additional objects in your software at a later point of time. Then you won't have to create new tables or add new columns in existing tables if you use this table structure.