Folder in DB Schema

From the followi开发者_StackOverflow中文版ng simple schema:

TABLE users
id
fname
lname

TABLE assets
id
userid (fk users.id)
assetname
assetdesc

Which would be the recommended way of created "folders" or "groups" for assets. I would also apply this to MESSAGES and other types that might make use of being organized in a folder-like structure.

add two other tables:

one for the 'folder'

folder
-------
id
name

and one for the contents

folder_content
--------------
folder_id
asset_id