如何使用字典更新Django模型中的字段?

Suppose I have a model like this:

假设我有一个这样的模型:

class Book(models.Model):
    num_pages = ...
    author = ...
    date = ...

Can I create a dictionary, and then insert or update the model using it?

我可以创建一个字典，然后使用它插入或更新模型吗?

d = {"num_pages":40, author:"Jack", date:"3324"}

3 个解决方案

#1

Here's an example of create using your dictionary d:

这里有一个使用字典d创建的例子:

Book.objects.create(**d)

To update an existing model, you will need to use the QuerySet filter method. Assuming you know the pk of the Book you want to update:

要更新现有的模型，需要使用QuerySet过滤器方法。假设你知道你想要更新的书的pk:

Book.objects.filter(pk=pk).update(**d)

#2

If you know you want to create it:

如果你知道你想创造它:

Book.objects.create(**d)

Assuming you need to check for an existing instance, you can find it with get or create:

假设您需要检查现有的实例，您可以使用get或create:

instance, created = Book.objects.get_or_create(slug=slug, defaults=d)
if not created:
    for attr, value in d.iteritems(): 
        setattr(instance, attr, value)
    instance.save()

As mentioned in another answer, you can also use the update function on the queryset manager, but i believe that will not send any signals out (which may not matter to you if you aren't using them). However, you probably shouldn't use it to alter a single object:

正如在另一个答案中所提到的，您也可以在queryset manager上使用update函数，但是我相信它不会发送任何信号(如果您不使用它们，这对您来说可能不重要)。但是，您可能不应该使用它来修改单个对象:

Book.objects.filter(id=id).update()

#3

Use ** for creating a new model. Loop through the dictionary and use setattr() in order to update an existing model.

使用**创建新模型。遍历字典并使用setattr()来更新现有模型。

From Tom Christie's Django Rest Framework

来自Tom Christie的Django Rest框架

https://github.com/tomchristie/django-rest-framework/blob/master/rest_framework/serializers.py

for attr, value in validated_data.items():
    setattr(instance, attr, value)
instance.save()

#1