python - auto_now_add 字段覆盖我的输入

Question

给定一个模型

class Foo(models.Model):
    bar = models.DateTimeField(auto_now_add=True)

当我这样做

my_foo = Foo.objects.create(bar=yesterday)

那么 my_bar.foo 不是昨天而是现在。我必须做的

my_foo = Foo.objects.create()
my_foo.bar = yesterday
my_foo.save()

过去不是这样，但对于 Django 1.8.17 是这样

Answer 1

来自docs :

The auto_now and auto_now_add options will always use the date in the default timezone at the moment of creation or update. If you need something different, you may want to consider simply using your own callable default or overriding save() instead of using auto_now or auto_now_add; or using a DateTimeField instead of a DateField and deciding how to handle the conversion from datetime to date at display time.

所以你应该这样做

bar = models.DateTimeField(default=date.today)