Help with SQL -> associations (Multiple JOINs)

[Gleb Mazovetskiy]

Is there a way to express this with associations?

@songs = Song.find_by_sql(%Q{
SELECT songs.*, song_playlist_relationships.playlist_id
FROM songs INNER JOIN song_playlist_relationships
ON songs.id = song_playlist_relationships.song_id
WHERE song_playlist_relationships.playlist_id IN
(#{@playlists.collect{|p| p.id}.join(',')})})


Thank you,
Gleb

 

[Matt H]

Is there a way to express this with associations?

=A0 =A0@songs =3D Song.find_by_sql(%Q{
=A0 =A0 =A0 =A0 =A0 =A0SELECT songs.*, song_playlist_relationships.playl= ist_id
=A0 =A0 =A0 =A0 =A0 =A0FROM songs INNER JOIN song_playlist_relationships
=A0 =A0 =A0 =A0 =A0 =A0 =A0ON songs.id =3D song_playlist_relationships.s= ong_id
=A0 =A0 =A0 =A0 =A0 =A0 =A0WHERE song_playlist_relationships.playlist_id= IN
(#{@playlists.collect{|p| p.id}.join(',')})})

Something like this should work. Double-check the :joins option in the
Rails documentation. I might have it wrong.

playlist_ids =3D @playlists.collect{|p| p.id}
Song.findall,
:conditions =3D> ["song_playlists_relationships.playlist_id IN (?)",
playlist_ids],
:joins =3D> :song_playlist_relationships)


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[Gleb Mazovetskiy]

Is there a way to express this with associations?

� �@songs = Song.find_by_sql(%Q{
� � � � � �SELECT songs.*, song_playlist_relationships.playlist_id
� � � � � �FROM songs INNER JOIN song_playlist_relationships
� � � � � � �ON songs.id = song_playlist_relationships.song_id
� � � � � � �WHERE song_playlist_relationships.playlist_id IN
(#{@playlists.collect{|p| p.id}.join(',')})})

Something like this should work. Double-check the :joins option in the
Rails documentation. I might have it wrong.

playlist_ids = @playlists.collect{|p| p.id}
Song.findall,
:conditions => ["song_playlists_relationships.playlist_id IN (?)",
playlist_ids],
:joins => :song_playlist_relationships)

Thank you, I'll look into it!


Cheers,

Gleb