尝试加入并获取 select_related 中给出的无效字段名称：'audio_links'。选项有：（无）

Question

我正在尝试对两个表进行联接 - 希望从 ReleasesAll 和 AudioLinks 返回所有数据。

错误

/api/release/0 处的字段错误

select_related 中给出的字段名称无效：“audio_links”。选择 是：（无）

models.py

class ReleasesAll(models.Model):
    id = models.IntegerField(primary_key=True)
    artist = models.CharField(max_length=255)
    all_artists = models.CharField(max_length=200)
    remixers = models.TextField(blank=True, null=True)
    format = models.CharField(max_length=80)
    title = models.CharField(max_length=255)
    label = models.CharField(max_length=255)
    label_no_country = models.CharField(max_length=255)

    class Meta:
        managed = False
        db_table = 'releases_all'

class AudioLinks(models.Model):
    release = models.ForeignKey('ReleasesAll', models.DO_NOTHING, db_column='release_id')
    track_number = models.IntegerField()
    track_name = models.CharField(max_length=500)
    url = models.CharField(max_length=500)
    m3u_link = models.TextField()
    type = models.CharField(max_length=50, blank=True, null=True)

    class Meta:
        managed = False
        db_table = 'audio_links'

views.py

class ListReleaseDetailView(generics.RetrieveUpdateDestroyAPIView):

    queryset = ReleasesAll.objects.all()
    serializer_class = ReleasesSerializer

    def get(self, request, *args, **kwargs):
        try:
            a_release = self.queryset.select_related('audio_links__release_id').get(pk=kwargs['release_id'])
            return Response(ReleasesSerializer(a_release).data)

        except ReleasesAll.DoesNotExist:
            return Response(
                data = {
                    "message": "{} does not exist".format(kwargs["release_id"])
                },
                status=status.HTTP_404_NOT_FOUND

如果我删除 select_related 则查询有效

Answer 1

您应该将prefetch_related 用于多个关系。 prefetch_related 的参数也应该是 related_name 值，或 audiolinks_set 在你的情况下：

a_release = self.queryset.prefetch_related('audiolinks_set').get(pk=kwargs['release_id'])

见docs:

select_related 仅限于单值关系 - 外键 并且是一对一的。