# models.py
class AuthorManager(models.Manager): # 新建一個類，繼承自models.Manager
  def name_count(self, keywords): # 添加自定義的查詢函數(shù)
   '''統(tǒng)計姓名中含有某些關鍵字的數(shù)量'''
    return self.filter(name__contains=keywords).count()
    
  def lt_age(self, age):
    '''查詢年齡小于指定年齡的信息'''
    return self.filter(age__lt=age)

class Author(models.Model):
  objects = AuthorManager() # 使用創(chuàng)建的自定義類覆蓋objects

  name = models.CharField(max_length=30, verbose_name='姓名')
  age = models.IntegerField(verbose_name='年齡')
  email = models.EmailField(null=True, verbose_name='郵箱')
  picture = models.ImageField(null=True, upload_to='static/upload/usring', verbose_name='用戶頭像')

  publisher = models.ManyToManyField(Publisher, null=True, verbose_name='出版社')

# views.py
def myself(request):
 '''自定義查詢函數(shù)'''
 # 統(tǒng)計名字中包含王字的
  num = Author.objects.name_count(keywords='王') 
 
 # 查詢年齡小于36的作者信息
  authors = Author.objects.lt_age(age=36)
  return render(request, 'name_count.html', locals())