模型中的Rails协会“父母”参考

Question

My following question might indicate a lack of proper understanding to how things really work in Ruby, Rails, or even general oOP concepts, and believe me i thought and searched a lot before asking, but i couldn't even form the correct search query to find the proper answer, so anyways here is what I would like to achieve ...

song = Artist.first.albums.first.songs.first 

this -to my understanding- will call the songs model and pass Artist model and Album model reference to the Song model to form an SQL query to fetch the data from the DB -since i am using ActiveRecord.

The real question; is there a way to know which Artist and Album called the Song model? this is useful specially in many-to-many relations where i don't want to pass an extra reference for the album/artist.

So if I have a function in my model for whatever reason it will be able to tell who created this Song instance?

Answer 1

That's too much chaining and it's overcomplicating things.

However, you could do song.artist or song.album to retrieve the song's Artist and Album, supposing you have the belongs_to :album and belongs_to :artist relationships declared in your Song model.

However, you could simply do:

artist = Artist.first
album = artist.albums.first
songs = album.songs

This way you have the Artist, his/her album you want (in this case the first one) and its songs all on different variables and you can handle them separately.