Django:在满足条件时更新Model中的字段

# 假设有一个名为MyModel的模型，其中有一个字段叫做status
from myapp.models import MyModel

# 查询满足条件的对象
instances = MyModel.objects.filter(some_condition=True)

# 更新字段
for instance in instances:
    instance.status = 'new_status'
    instance.save()

# 直接更新满足条件的所有记录
MyModel.objects.filter(some_condition=True).update(status='new_status')

from django.db.models.signals import pre_save
from django.dispatch import receiver
from myapp.models import MyModel

@receiver(pre_save, sender=MyModel)
def update_status(sender, instance, **kwargs):
    if some_condition:
        instance.status = 'new_status'

if MyModel.objects.filter(some_condition=True).exists():
    MyModel.objects.filter(some_condition=True).update(status='new_status')
else:
    print("No records found matching the condition.")

from django.db import transaction

with transaction.atomic():
    MyModel.objects.filter(some_condition=True).update(status='new_status')