cascading config

[lajkonik86]

heey i need some cascading config in my database

i have things defined at 3 levels

• account
• site
• thread

so in my database i would like to query the effective config
thread has the highest level and account the lowest

example
- account: language = french
- site: language = english
- thread: null

I was planning to store the data in a config table as such:
level (-2 = account -1 = site >1 = some thread id)
config name
config value

So how do i just get the config name and value with the highest level?
Something with select unique?

Cheers,
Thierry