django-rest-framework - select_related queryset with ModelSerializer in Django rest framework

Question

我正在尝试将“select_related”查询集方法与 DRF 序列化程序一起使用，
但是这个例子还是做了很多sql查询。

如何从 select_related 方法中获取相关对象“model_b”？

class Model_A(models.Model):
    title = models.CharField(max_length=100)
    description = models.TextField()
    model_b = models.ForeignKey(Model_B, null=True, blank=True)

class Model_B(models.Model):
    title = models.CharField(max_length=100)


class Model_A_Serializer(serializers.ModelSerializer):
    model_b = Model_B_Serializer(source="model_b")
    class Meta:
        model = Model_A
        fields = ('title', 'model_b')

class Model_B_Serializer(serializers.ModelSerializer):
    class Meta:
        model = Model_B


class Model_A_View(viewsets.ModelViewSet):
    serializer_class = Model_A_Serializer
    queryset = Model_A.objects.select_related('model_b').all()

Answer 1

Use prefetch_related instead.

queryset = Model_A.objects.all().prefetch_related('model_b')

此外，您可以使用 this answer 将 sql 查询记录到控制台。