oh you need to add the has_many for the join table has_many :meter_goup has_many :meters, :through => :meter_group
On Aug 18, 2:41 pm, Rick R <[email protected]> wrote: > On Wed, Aug 18, 2010 at 3:30 PM, Me <[email protected]> wrote: > > I would start by getting rid of the :foreign_key specifications > > unless you are doing something non standard. > > Ok, thanks. I removed them. (Didn't fix the issue but does look a lot > cleaner.) > > > > > > > On Aug 18, 2:26 pm, Rick R <[email protected]> wrote: > > > On Wed, Aug 18, 2010 at 3:04 PM, Rick R <[email protected]> wrote: > > > > I'm a rails newb and have been Googling about this, but I'm still > > stumped. > > > > > Not showing everything here, but basically it should be a pretty common > > > > setup so I'm sure others know what I'm doing wrong. > > > > > - A meter can belong to many meter_groups > > > > - A meter_group can have many meters. > > > > - A user can 'subscribe' to viewing a meter_group (Subscription) so he > > > > should be able to see the meters that are in that meter_group of the > > > > subscription (think subscribing to a topic in a forum.) > > > > > Initially I was only allowing a single meter to belong to only one > > > > meter_group and the following test and relationship of a Subscription > > worked > > > > fine: > > > > > class Subscription < ActiveRecord::Base > > > > belongs_to :user, :foreign_key => "user_id" > > > > belongs_to :meter_group, :foreign_key => "meter_group_id" > > > > has_many :meters, :through => :meter_group > > > > end > > > > > test "group1 and group2 belong to rachel" do > > > > user = User.find_by_login("rachel") > > > > subscriptions = Subscription.find_all_by_user_id(user.id) > > > > subscriptions.each do |s| > > > > meters = s.meters > > > > meters.each do |m| > > > > puts "meter = #{p m}" > > > > end > > > > end > > > > end > > > > As a side note, there isn't an issue if I try to get meters directly from > > > the meter_group. For example in the above test it works if changed to: > > > > test "group1 and group2 belong to rachel" do > > > user = User.find_by_login("rachel") > > > subscriptions = Subscription.find_all_by_user_id(user.id) > > > subscriptions.each do |s| > > > *meter_group = s.meter_group > > > meters = meter_group.meters* > > > meters.each do |m| > > > puts "meter = #{p m}" > > > end > > > end > > > end > > > > > However now things are not working since I created some HABTM > > relationships > > > > for meter_group and meters. I end up with the following error: > > > > > ActiveRecord::HasManyThroughSourceAssociationMacroError: Invalid source > > > > reflection macro :has_and_belongs_to_many for has_many :meters, > > :through => > > > > :meter_group. Use :source to specify the source reflection. > > > > > Here are some of the other relevant tables and migrations (stripped of > > a > > > > few non-related fields): > > > > > class MeterGroup < ActiveRecord::Base > > > > belongs_to :user, :foreign_key => "user_id" > > > > has_and_belongs_to_many :meters > > > > end > > > > > class Meter < ActiveRecord::Base > > > > has_and_belongs_to_many :meter_groups > > > > belongs_to :user, :foreign_key => "user_id" > > > > end > > > > > #Migrations (removed some cols and drop section) > > > > > class CreateMeterGroups < ActiveRecord::Migration > > > > def self.up > > > > create_table :meter_groups do |t| > > > > t.string :name > > > > t.string :description > > > > t.integer :user_id > > > > > t.timestamps > > > > end > > > > end > > > > end > > > > > class CreateMeters < ActiveRecord::Migration > > > > def self.up > > > > create_table :meters do |t| > > > > t.integer :meter_type_id > > > > t.integer :scale_id > > > > t.integer :user_id > > > > t.string :name > > > > t.string :description > > > > > t.timestamps > > > > end > > > > end > > > > end > > > > > class CreateMetersMeterGroups < ActiveRecord::Migration > > > > def self.up > > > > create_table :meter_groups_meters, :id => false do |t| > > > > t.integer :meter_id > > > > t.integer :meter_group_id > > > > > t.timestamps > > > > end > > > > end > > > > end > > > > > class CreateSubscriptions < ActiveRecord::Migration > > > > def self.up > > > > create_table :subscriptions do |t| > > > > t.integer :user_id > > > > t.integer :meter_group_id > > > > > t.timestamps > > > > end > > > > end > > > > end > > > > -- > > > Rick R > > > -- > > You received this message because you are subscribed to the Google Groups > > "Ruby on Rails: Talk" group. > > To post to this group, send email to [email protected]. > > To unsubscribe from this group, send email to > > [email protected]<rubyonrails-talk%2Bunsubscrib > > [email protected]> > > . > > For more options, visit this group at > >http://groups.google.com/group/rubyonrails-talk?hl=en. > > -- > Rick R -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
