Question

我要计算同一产品的用户数量

models.py

class Product(models.Model):
   pass
class User(models.Model):
   product = models.ForeignKey(Product)
   age = models.IntegerField(blank=True, null=True)

User.objects.filter(age__gt=18).annotate(product_count=Count('product_id'))

输出sql

SELECT
  "user"."product_id"
  COUNT("user"."product_id") AS "product_count"
FROM "user"
WHERE "user"."age" > 18
GROUP BY "user"."id";

所需的SQL ：

SELECT
  "user"."product_id"
  COUNT("user"."product_id") AS "product_count"
FROM "user"
WHERE "user"."age" > 18
GROUP BY "user"."product_id";

Answer 1

我认为这没有任何意义。您想要的可能是这样：

Product.objects.annotate(user_count=Count('user'))

Django通过不同于id的方式生成分组

1 个答案: