3 column :hbtm?

rubyonrails-talk
1

A Song :has and belongs to many Playlists. I want to store additional information about a song in a given playlist, i.e. the number of request of this song in a playlist.

Here is an example

Playlist a:

Song A|5 requests| Song B|3 requests|

Playlist b:

Song A|2 requests| Song B|4 requests|

In SQL I would add an extra column :number_of_requests to the songs_playlists table. But how do I do it with pure ActiveRecord?

2

You can make the join table be a fully fledged ActiveRecord model (it will need an id column) and add the new columns to it. Then use has_many :through rather then habtm

Colin

3

How would I do this? I am new to Rails. :has_one request_count :through => "what do i put here? where do I store it?"

Thank you

4

Have a look at the rails guides at http://guides.rubyonrails.org/ particularly the one on ActiveRecord Associations (assuming you have already looked at the Getting Started one). Google will provide lots of help too.

Colin

5

Thank you, everyone, I made it work through :through :slight_smile: