django模型中如何创建基于其他表的触发器更新字段

Question

I have two models, In activity model status is column name this column row has to update from 'Pending' to 'Done', when status column row update from 'Pending' to 'Done' in Item model.It has to update automatically when db field get change.

class Activity(models.Model):
   a_id = models.AutoField(primary=True, unique=True)
   status = models.CharField(max_length=225, blank=True,null=True, default="Pending")
class Item(models.Model):
   item_id = models.AutoField(primary=True, uniue=True)
   status = models.CharField(max_length=225, blank=True, null=True, default="Pending")
   activityid = models.ForeginKey(Activity, on_delete=models.CASCADE, 
                                           related_name="activitynt")

Answer 1

In models.py use signals to update your status

models.py

from django.db.models.signals import post_save
from django.dispatch import receiver

@receiver(post_save, sender=Activity)
def update_item_status(sender, instance,created, **kwargs):
    Item.objects.filter(activityid=instance.pk).update(status=instance.status)