Django模型中的非数据库字段 [英] Non-database field in Django model

问题描述

可以在Django模型中有一个不能存储在数据库中的字段。

例如：

Is it possible to have a field in a Django model which does not get stored in the database.
For example:

class Book(models.Model):
    title = models.CharField(max_length=75)
    description models.CharField(max_length=255, blank=True)
    pages = models.IntegerField()
    none_db_field = ????

然后我可以做

book = Book.objects.get(pk=1)
book.none_db_field = 'some text...'
print book.none_db_field

感谢

推荐答案

只要您不希望该属性持久存在，我不明白为什么您无法创建像您所描述的属性。我实际上在某些模型上做同样的事情来确定哪些是可编辑的。

As long as you do not want the property to persist, I don't see why you can't create a property like you described. I actually do the same thing on certain models to determine which are editable.

class Email(EntryObj):
    ts = models.DateTimeField(auto_now_add=True)
    body = models.TextField(blank=True)
    user = models.ForeignKey(User, blank=True, null=True)
    editable = False
    ...


class Note(EntryObj):
    ts = models.DateTimeField(auto_now_add=True)
    note = models.TextField(blank=True)
    user = models.ForeignKey(User, blank=True, null=True)
    editable = True

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