polymorphic-associations

I've read some of Bill Karwin's answers about single table inheritance and think this approach would be good for the setup I am considering: Playlist -------- id AUTO_INCREMENT title TeamPlaylist ------------ id REFERENCES Playlist.id teamId REFERENCES Team.id UserPlaylist ------------ id REFERENCES Playlist.id userId REFERENCES User.id PlaylistVideo ------------- id playlistId REFERENCES Playlist.id videoId REFERENCES Video.id All the CASCADE options are set to DELETE which will work correctly for when a Playlist is deleted, however, what happens if a User or Team is deleted? ie. If a User is

I try to create a polymorphic association, what is common in Rails but unfortunately not in Yii2. As part of the implementation I need to define the relation: public function getImages() { return $this->hasMany(RecipeImage::className(), ['imageable_id' => 'id', 'imageable_type' => 'Person']); } But this doesn't work, because 'Person' is treated as an attribute of the current model, but it is a constant (class name for the polymorphic association). If I try to use 'andWhere' it adds the condition of course in a WHERE clause instead of the ON clause, causing that only records with existing image

A User can Upload a Clip via the Clips Scaffold , this clip either belongs to a Show and or an Album (Show Controller, Album Controller). A user can have ONLY ONE SHOW MANY ALBUMS What i'm trying to accomplish: A User can Upload Clips , these clips can be attached to either a Show or/and an Album For a more detailed overview take a look at the image below: Problem #1 What i'm not understanding is the associations i must use. My current Models: User Model : has_many :clips, dependent: :destroy has_one :show, dependent: :destroy has_many :albums, dependent :destroy Clip Model : belongs_to :user

Here are my models: class Lesson < ActiveRecord::Base belongs_to :topic, :polymorphic => true validates_presence_of :topic_type, :topic_id end class Subject < ActiveRecord::Base has_many :lessons, :as => :topic end class Category < ActiveRecord::Base has_many :lessons, :as => :topic end Now, what I need is a form that will allow the user to create or update Lessons. The questions is, how can I provide a select menu that offers a mix of Subjects and Categories? (To the user, on this particular form, Subjects and Categories are interchangeable, but that's not the case elsewhere.) Ideally, this

I have the following route definition: resources :documents do collection do post :filter end end and the following model structure: class Document < ActiveRecord::Base belongs_to :documentable, :polymorphic => true end class User < ActiveRecord::Base has_many :documents, :as => :documentable end and controller structure: class DocumentsController < ApplicationController def index # not important end def filter # not important end end I can easily in a view say: polymorphic_path([@user, Document]) to get the path /users/1/documents , but I want to be able to say: filter_polymorphic_path([@user

I have a polymorphic relationship with address being able to both be owned by a member or a dependent. Everything looked great until I realized that I wouldn't know what type of object was creating it unless I'm missing something. Is there a way to tell the routing file to include the type of object? Models: class Member < ActiveRecord::Base has_one :address, as: :person, dependent: :destroy end class Dependent < ActiveRecord::Base has_one :address, as: :person, dependent: :destroy end class Address < ActiveRecord::Base belongs_to :person, polymorphic: true end Controller: def new @person = ??