I was going through the wiki article http://www.yiiframework.com/wiki/385/displaying-sorting-and-filtering-hasmany-manymany-relations-in-cgridview/ and its source code in github https://github.com/yjeroen/ManyMany
Since i was having several MANY_MANY relations in my DB, i came across "through" in above article.
I im not able to understand, why author have used relation in model Gener.php as
'songs' => array(self::MANY_MANY, 'Song', 'song_genre(genre_id, song_id)')
where as in Song.php as
'hasGenres' => array(self::HAS_MANY, 'SongGenre', 'song_id'),
'genres'=> array(self::HAS_MANY, 'Genre', 'genre_id', 'through'=>'hasGenres'),
why not used in Song.php like this :
'genres'=> array(self::MANY_MANY, 'Song', song_genre(song_id,gener_id)')
what is difference between these two? where should we use which? please help. Thanks