如何设置字段值过期时间？

Question

我有这样的模型 User：

class User(AbstractBaseUser, PermissionsMixin):
    myfield_choices = (('foo', 'First value'), ('bar', 'Second value')

    myfield = CharField(choices=choices)
    
    objects = BaseUserManager()

我在字段 myfield 中设置值 foo。我想在字段 myfield 中设置值 bar 1 天后，此期限到期后，该值会再次自动变为 foo。
我该如何设置该到期时间？是否有任何原生的 django 工具？

Answer 1

我假设你对 Django 有点陌生，所以我会建议一个不基于任务队列的解决方案（比如 celery 或 dramatiq）。

为清楚起见，假设我们正在实施 ban_user 和 unban_user 机制。首先我们必须更新 User 模型：

class User(AbstractBaseUser, PermissionsMixin):
    class BanStatus(models.TextChoices):
        ACTIVE = "ACTIVE", "ACTIVE"
        BANNED_FOR_DAY = "BANNED_FOR_DAY", "BANNED_FOR_DAY"

    ban_status = models.TextField("Ban status", choices=BanStatus.choices)
    banned_for_day_at = models.DateTimeField("Banned for day at", null=True)

然后我们必须实施确切的机制。我更愿意在某些 your-app-name/logic/ban_user.py 文件中执行此操作：

from django.utils import timezone
# And also an import of User.


def ban_user_for_day(user: User):
    user.ban_status = User.BanStatus.BANNED_FOR_DAY
    user.banned_for_day_at = timezone.now()
    user.save()


def revoke_ban_user_for_day(user: User):
    user.ban_status = User.BanStatus.ACTIVE
    user.banned_for_day_at = None
    user.save()

因此我们可以从视图调用ban_user_for_day。至于revoke_ban_user_for_day，最简单的组织调用方式是Command，可以周期性调用，例如cron。你可以把它放在 your-app-name/management/commands/revoke_ban_user_for_day.py

from django.core.management import BaseCommand
from django.utils import timezone
# And also imports of User and revoke_ban_user_for_day.


class Command(BaseCommand):
    def handle(self, *args, **options):
        user_list_for_revoke = User.objects.filter(
            ban_status=User.BanStatus.ACTIVE,
            banned_for_day_at__lte=timezone.now() - timezone.timedelta(days=1)
        ).all()

        for user in user_list_for_revoke:
            revoke_ban_user_for_day(user)

就是这样。如果您将此 Command 设置为每分钟一次运行，则 User 应该解禁与实际解禁之间的延迟不会超过 1 分钟.

如何设置字段值过期时间？

How to set field value expiration time?

django

postgresql

django-models

python-3.x

django-rest-framework