django rest framework 外键序列化方法与问题总结

为前端提供数据时，往往是这样的json

{
    'album_name': 'Undun',
    'artist': 'The Roots',
    'tracks': 01
}......

如果需要外键字段对应表的详细信息，像这样

{
    'album_name': 'The Grey Album',
    'artist': 'Danger Mouse',
    'tracks': [
        {'order': 1, 'title': 'Public Service Announcement', 'duration': 245},
        {'order': 2, 'title': 'What More Can I Say', 'duration': 264},
        {'order': 3, 'title': 'Encore', 'duration': 159},
        ...
    ],
}

要怎么配置？

查看 django rest framework 官网说明http://www.django-rest-framework.org/api-guide/relations/  

虽然讲到了怎么操作，但是不详细，屡屡遇坑

所用到的model

class Album(models.Model):
    album_name = models.CharField(max_length=100)
    artist = models.CharField(max_length=100)

class Track(models.Model):
    album = models.ForeignKey(Album,   on_delete=models.CASCADE)
    order = models.IntegerField()
    title = models.CharField(max_length=100)
    duration = models.IntegerField()

    class Meta:
        unique_together = ('album', 'order')
        ordering = ['order']

    def __unicode__(self):
        return '%d: %s' % (self.order, self.title)

配置serializer

class TrackSerializer(serializers.ModelSerializer):
    class Meta:
        model = Track
        fields = ('order', 'title', 'duration')

class AlbumSerializer(serializers.ModelSerializer):
    tracks = TrackSerializer(many=True, read_only=True)

    class Meta:
        model = Album
        fields = ('album_name', 'artist', 'tracks')

好像搞定了，运行起来才发现有个坑

Got AttributeError when attempting to get a value for field 'tracks' on serializer 'AlbumSerializer'

没有tracks字段，咋整？

原来只要在model foreignkey里面添加

 related_name='tracks',

 album = models.ForeignKey(Album,  related_name='tracks', on_delete=models.CASCADE)

就搞定了。。

官网例子里有，但是很容易忽略，这里提出来，希望大家注意

为前端提供数据时，往往是这样的json

{
    'album_name': 'Undun',
    'artist': 'The Roots',
    'tracks': 01
}......

如果需要外键字段对应表的详细信息，像这样

{
    'album_name': 'The Grey Album',
    'artist': 'Danger Mouse',
    'tracks': [
        {'order': 1, 'title': 'Public Service Announcement', 'duration': 245},
        {'order': 2, 'title': 'What More Can I Say', 'duration': 264},
        {'order': 3, 'title': 'Encore', 'duration': 159},
        ...
    ],
}

要怎么配置？

查看 django rest framework 官网说明http://www.django-rest-framework.org/api-guide/relations/  

虽然讲到了怎么操作，但是不详细，屡屡遇坑

所用到的model

class Album(models.Model):
    album_name = models.CharField(max_length=100)
    artist = models.CharField(max_length=100)

class Track(models.Model):
    album = models.ForeignKey(Album,   on_delete=models.CASCADE)
    order = models.IntegerField()
    title = models.CharField(max_length=100)
    duration = models.IntegerField()

    class Meta:
        unique_together = ('album', 'order')
        ordering = ['order']

    def __unicode__(self):
        return '%d: %s' % (self.order, self.title)

配置serializer

class TrackSerializer(serializers.ModelSerializer):
    class Meta:
        model = Track
        fields = ('order', 'title', 'duration')

class AlbumSerializer(serializers.ModelSerializer):
    tracks = TrackSerializer(many=True, read_only=True)

    class Meta:
        model = Album
        fields = ('album_name', 'artist', 'tracks')

好像搞定了，运行起来才发现有个坑

Got AttributeError when attempting to get a value for field 'tracks' on serializer 'AlbumSerializer'

没有tracks字段，咋整？

原来只要在model foreignkey里面添加

 related_name='tracks',

 album = models.ForeignKey(Album,  related_name='tracks', on_delete=models.CASCADE)

就搞定了。。

官网例子里有，但是很容易忽略，这里提出来，希望大家注意