Django 模型，自定义函数 [英] Django models, custom functions

问题描述

我正在用 django 创建简单的应用程序.另外，我意识到我经常做某种操作.例如，我经常需要获取所有具有 isPublick = True 的文章对象.所以我在想是否可以在模型中定义 get_published 函数?

如果模型看起来像这样(简化)

class 文章(models.Model):标题 = 模型.CharField(...)isPublished = models.BooleandField()def get_active(self):返回文章.objects.filter(isPublicshed = 1)

但这种方式行不通

你能提出一种实现该功能的方法吗?

解决方案

您可能想要的是 自定义管理器

来自 Django 文档:

 # 一个名为对象"的自定义管理器示例.类 PersonManager(models.Manager):def get_fun_people(self):返回 self.filter(fun=True)类人(模型.模型):first_name = models.CharField(max_length=30)last_name = models.CharField(max_length=30)乐趣 = 模型.BooleanField()对象 = PersonManager()def __unicode__(self):返回 u"%s %s" % (self.first_name, self.last_name)

然后允许您执行以下操作:

<预><代码>>>>p1 = Person(first_name='Bugs', last_name='Bunny', fun=True)>>>p1.save()>>>p2 = Person(first_name='Droopy', last_name='Dog', fun=False)>>>p2.save()>>>Person.objects.get_fun_people()[<人物:兔八哥>]

I am creating simple application with django. Also, I realized that I am doing some kind of operations very often. For example I often need to get all Article objects which have isPublick = True. So I am thinking is that possible to define get_published function in model?

if models looks like this (simplified)

class Article(models.Model):
    title = models.CharField(...)
    isPublished = models.BooleandField()

    def get_active(self):
       return Article.objects.filter(isPublicshed = 1)

But it doesn't work this way

Can you suggest a way of implementing the function?

解决方案

What you probably want is a custom manager

From the django docs:

        # An example of a custom manager called "objects".

class PersonManager(models.Manager):
    def get_fun_people(self):
        return self.filter(fun=True)

class Person(models.Model):
    first_name = models.CharField(max_length=30)
    last_name = models.CharField(max_length=30)
    fun = models.BooleanField()
    objects = PersonManager()

    def __unicode__(self):
        return u"%s %s" % (self.first_name, self.last_name)

which then allows you to do something like:

>>> p1 = Person(first_name='Bugs', last_name='Bunny', fun=True)
>>> p1.save()
>>> p2 = Person(first_name='Droopy', last_name='Dog', fun=False)
>>> p2.save()
>>> Person.objects.get_fun_people()
[<Person: Bugs Bunny>]

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