如何在特定时间后自动更改Django Model字段？

from django.db.models.signals import pre_save
from django.dispatch import receiver
from django.utils import timezone

@receiver(pre_save, sender=YourModel)
def update_field(sender, instance, **kwargs):
    if instance.field_to_change is None:
        # 在这里判断是否需要更改字段
        # 如果需要更改字段，可以使用instance.field_to_change = new_value进行更改
        # new_value是你想要设置的新值
        pass

from datetime import datetime

@receiver(pre_save, sender=YourModel)
def update_field(sender, instance, **kwargs):
    if instance.field_to_change is None:
        specific_time = datetime(2022, 1, 1, 0, 0, 0)  # 设置特定时间
        if timezone.now() >= specific_time:
            instance.field_to_change = new_value

@receiver(pre_save, sender=YourModel)
def update_field(sender, instance, **kwargs):
    if instance.field_to_change is None:
        specific_time = datetime(2022, 1, 1, 0, 0, 0)  # 设置特定时间
        if timezone.now() >= specific_time:
            instance.field_to_change = 'new_value'

from django.apps import AppConfig

class YourAppConfig(AppConfig):
    default_auto_field = 'django.db.models.BigAutoField'
    name = 'your_app_name'

    def ready(self):
        import your_app_name.signals  # 替换为你的信号接收器函数所在的文件路径