Django - a source in serializers that results in too many database queries

Question

I am trying to create a connection between composer and performer in Django. I have the following models:

class Artist(models.Model):
    gid = models.CharField(max_length=63, blank=True)
    name = models.CharField(max_length=255, blank=True)
    begin_life = models.CharField(max_length=31, blank=True)
    end_life = models.CharField(max_length=31, blank=True)
    type = models.CharField(max_length=1, blank=True)
    gender = models.CharField(max_length=1, blank=True)

class Song(models.Model):
    gid = models.CharField(max_length=63, blank=True)
    title = models.CharField(max_length=255, blank=True)
    artist = models.ForeignKey('Artist', related_name='songs_artist')
    album = models.ForeignKey('Album', related_name='songs_album')
    length = models.IntegerField(default=0)

I created my ArtistSerializer to get all artist songs when I get information about any particular artist. This is the created serializer:

class ArtistSerializer(serializers.ModelSerializer):
    songs_artist = SongSerializer(source='songs_artist')
    class Meta:
        model = Artist
        fields = ('name', 'type', 'gender', 'begin_life', 'end_life', 'songs_artist')

class SongSerializer(serializers.ModelSerializer):
    artist = SongArtistSerializer()
    album = SongAlbumSerializer()
    class Meta:
        model = Song
        fields = ('id', 'title', 'artist', 'album', 'length')

class SongArtistSerializer(serializers.ModelSerializer):
    class Meta:
        model = Artist
        fields = ('id', 'name')

My artist’s quick GET profiling revealed some troubling facts. The following are profiling results sorted by time and number of calls: http://pastebin.com/bwcKsn2i .

But, when I deleted the field songs_artistfrom my serializer, the following was the output of the profiler: http://pastebin.com/0s5k4w7i .

, 1240 , source!

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Answer 1

Django REST Framework , , N + 1. , Django .

ForeignKey select_related , .

ManyToMany GenericForeignKey prefetch_related. , , select_related.

get_queryset , , Django REST Framework .