爲什麼我的has_many：通過關聯在刪除時不能正常工作？

Question

我的has_many：通過發行版/產品/曲目上的關聯似乎刪除了跟蹤並在releases_tracks/products_tracks表中刪除了孤立的關聯。我看不出我出錯的地方，我認爲默認行爲是隻刪除關聯。任何人都可以幫忙嗎？

我的模型：

class Track < ActiveRecord::Base 
    has_many :releases_tracks 
    has_many :tracks, :through => :releases_tracks 

    has_many :products_tracks 
    has_many :products, :through => :products_tracks 
end 

class Release < ActiveRecord::Base 
    has_many :releases_tracks 
    has_many :tracks, :through => :releases_tracks 
end 

class Product < ActiveRecord::Base 
    has_many :products_tracks 
    has_many :tracks, :through => :products_tracks 
    before_save do 
    self.track_ids = self.releases_track_ids 
    end 
end 

class ProductsTrack < ActiveRecord::Base 
    belongs_to :product 
    belongs_to :track 
end 

class ReleasesTrack < ActiveRecord::Base 
    belongs_to :release 
    belongs_to :track 
end 

我的軌道控制（用於摧毀行動）：

class TracksController < ApplicationController 
    before_filter :get_track_parent 

def destroy 
    @track = @parent.tracks.find(params[:id]) 
    @track.destroy 
    redirect_to @parent 
end 

private 

def get_track_parent 
    if params[:product_id].present? 
    @parent = Product.find(params[:product_id]) 
    elsif params[:release_id].present? 
    @parent = Release.find(params[:release_id]) 
    end 
end 
end 

我消滅在發佈鏈接查看：

<%= link_to image_tag("icons/delete.png"), release_track_path(@release,track), :confirm => 'Are you sure?', :method => :delete %> 

最後，我銷燬產品視圖中的鏈接：

<%= link_to image_tag("icons/delete.png"), product_track_path(@product,track), :confirm => 'Are you sure?', :method => :delete %> 

Answer 1

首先，您需要爲您的協會:dependent => :destroy選項：

class Track < ActiveRecord::Base 
    has_many :releases_tracks, :dependent => :destroy 
    has_many :releases, :through => :releases_tracks # also note you had here :tracks instead of :releases 

    has_many :products_tracks, :dependent => :destroy 
    has_many :products, :through => :products_tracks 
end 

而且，如果你還想要刪除曲目刪除版本或產品時，添加以下:dependent => :destroy S：

class Release < ActiveRecord::Base 
    has_many :releases_tracks, :dependent => :destroy 
    has_many :tracks, :through => :releases_tracks 
end 

class Product < ActiveRecord::Base 
    has_many :products_tracks, :dependent => :destroy 
    has_many :tracks, :through => :products_tracks 
    before_save do 
    self.track_ids = self.releases_track_ids 
    end 
end 

class ProductsTrack < ActiveRecord::Base 
    belongs_to :product 
    belongs_to :track, :dependent => :destroy 
end 

class ReleasesTrack < ActiveRecord::Base 
    belongs_to :release 
    belongs_to :track, :dependent => :destroy 
end