DjangoAggregation聚合使用方法解析-创新互联

在当今根据需求而不断调整而成的应用程序中，通常不仅需要能依常规的字段，如字母顺序或创建日期，来对项目进行排序，还需要按其他某种动态数据对项目进行排序。Djngo聚合就能满足这些要求。

以下面的Model为例

from django.db import models
 
class Author(models.Model):
  name = models.CharField(max_length=100)
  age = models.IntegerField()
class Publisher(models.Model):
  name = models.CharField(max_length=300)
  num_awards = models.IntegerField()
class Book(models.Model):
  name = models.CharField(max_length=300)
  pages = models.IntegerField()
  price = models.DecimalField(max_digits=10, decimal_places=2)
  rating = models.FloatField()
  authors = models.ManyToManyField(Author)
  publisher = models.ForeignKey(Publisher)
  pubdate = models.DateField() 
class Store(models.Model):
  name = models.CharField(max_length=300)
  books = models.ManyToManyField(Book)
  registered_users = models.PositiveIntegerField()