通过子类(产品)从类别类访问许多Tomany字段(标签) 类别->产品->标签

Question

这是我的模型文件的代码:

from django.db import models
# Create your models here.
class Category(models.Model):
name = models.CharField(max_length=255)
def __str__(self):
return self.name
class Product(models.Model):
category = models.ForeignKey(Category, on_delete=models.CASCADE, related_name='products')
name = models.CharField(max_length=255)
price = models.DecimalField(decimal_places=2, max_digits=9)
def __str__(self):
return self.name
class Label(models.Model):
name = models.CharField(max_length=255)
products = models.ManyToManyField(Product,  related_name='labels')
def __str__(self):
return self.name

现在我想访问许多字段，即标签从类别请帮帮我

Thanks in advance

Answer 1

你可以这样试试。

# first get the single category object 
category = Category.objects.get(pk=1)
# querying products in this category 
products = category.products.all()
# now filter the Label model based on the category products 
labels = Label.objects.filter(products__in=products)