Double join with habtm in ActiveRecord
- by Daniel Huckstep
I have a weird situation involving the need of a double inner join. I have tried the query I need, I just don't know how to make rails do it.
The Data
Account (has_many :sites)
Site (habtm :users, belongs_to :account)
User (habtm :sites)
Ignore that they are habtm or whatever, I can make them habtm or has_many :through.
I want to be able to do
@user.accounts
or
@account.users
Then of course I should be able to do
@user.accounts < @some_other_account
And then have @user.sites include all the sites from @some_other_account.
I've fiddled with habtm and has_many :through but can't get it to do what I want.
Basically I need to end up with a query like this (copied from phpmyadmin. Tested and works):
SELECT accounts.*
FROM accounts
INNER JOIN sites ON sites.account_id = accounts.id
INNER JOIN user_sites ON sites.id = user_sites.site_id
WHERE user_sites.user_id = 2
Can I do this? Is it even a good idea to have this double join? I am assuming it would work better if users had the association with accounts to begin with, and then worry about getting @user.sites instead, but it works better for many other things if it is kept the way it is (users <- sites).
