创建Django模型或更新（如果存在）(Create Django model or update if exists)

创建Django模型或更新（如果存在）(Create Django model or update if exists)

我想创建一个模型对象，如Person，如果人的id不存在，或者我会得到那个人的对象。

创建新人的代码如下：

class Person(models.Model): identifier = models.CharField(max_length = 10) name = models.CharField(max_length = 20) objects = PersonManager() class PersonManager(models.Manager): def create_person(self, identifier): person = self.create(identifier = identifier) return person

但我不知道在哪里检查并获得现有的人物。

I want to create a model object, like Person, if person's id doesn't not exist, or I will get that person object.

The code to create a new person as following:

class Person(models.Model): identifier = models.CharField(max_length = 10) name = models.CharField(max_length = 20) objects = PersonManager() class PersonManager(models.Manager): def create_person(self, identifier): person = self.create(identifier = identifier) return person

But I don't know where to check and get the existing person object.

最满意答案

如果您正在寻找“更新如果存在其他创建”用例，请参阅@Zags优秀的答案

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Django已经有一个get_or_create ， https : get_or_create

对你来说可能是：

id = 'some identifier' person, created = Person.objects.get_or_create(identifier=id) if created: # means you have created a new person else: # person just refers to the existing one

If you're looking for "update if exists else create" use case, please refer to @Zags excellent answer

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Django already has a get_or_create, https://docs.djangoproject.com/en/dev/ref/models/querysets/#get-or-create

For you it could be :

id = 'some identifier' person, created = Person.objects.get_or_create(identifier=id) if created: # means you have created a new person else: # person just refers to the existing one