django - 过滤中介ManyToMany django

Question

class Ingredient(Model):
    name = CharField(max_length=55, unique=True)

    def __str__(self):
        return self.name

    class Meta:
        ordering = ('name',)



class Product(Model):
    name = CharField(max_length=55)

    def __str__(self):
        return self.name

    class Meta:
        ordering = ('name', )


class ProductIngredient(Model):
    product = ForeignKey(Product, on_delete=CASCADE, related_name='product_ingredients')
    ingredient = ForeignKey(Ingredient, on_delete=CASCADE)
    optional = BooleanField(default=False)

    class Meta:
        unique_together = (('product', 'ingredient'),)
        ordering = ('product__name',)

    def __str__(self):
        return f'{self.product} - {self.ingredient}'

我想做两个查询：

• 选择所有产品，其成分包含草莓和牛奶
• 选择所有产品，其成分包含草莓或牛奶

第一个查询是：Product.objects.prefetch_related('product_ingredients__ingredient').filter(product__ingredients__ingredient__name='strawberry').filter(product__ingredients__ingredient__name='milk')

我需要distinct在第一个查询中写吗？如何编写第二个查询？

标签： djangodjango-models

Answer 1

使用Q 对象进行复杂的查找

Product.objects.prefetch_related('product_ingredients__ingredient').filter(Q(product__ingredients__ingredient__name='strawberry')|Q(product__ingredients__ingredient__name='milk'))