ActiveRecord inner joins

Tim Booher wrote:

User -> Order -> Registration <- Camp

So a user has many orders, orders have many registrations and camps have
many registrations.

I have all the associations written up correctly, but I want to know how
to get all the users for a particular camp.

class Camp < ActiveRecord::Base
  has_many :registrations
  has_many :orders, :through => :registrations, :uniq => true, :include
=> :user
  :

@camp = Camp.find_by_name("band camp")
mycampers = @camp.orders.map {|o| o.user}.uniq

Mark Bush wrote:

Tim Booher wrote:

User -> Order -> Registration <- Camp

So a user has many orders, orders have many registrations and camps have
many registrations.

I have all the associations written up correctly, but I want to know how
to get all the users for a particular camp.

class Camp < ActiveRecord::Base
  has_many :registrations
  has_many :orders, :through => :registrations, :uniq => true, :include
=> :user
  :

@camp = Camp.find_by_name("band camp")
mycampers = @camp.orders.map {|o| o.user}.uniq

this is great! thanks for your help. is :uniq a custom method of
has_many :through ?

best,

tim

Tim Booher wrote:

this is great! thanks for your help. is :uniq a custom method of
has_many :through ?

You can use ":uniq => true" for any "has_many" (and HABTM) association,
however it is most useful for ":through" types since direct associations
that need to be unique collections can be handled in the model
validation to prevent duplicates in the first place.