Question

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

class Connector(models.Model):
    connector_id = models.AutoField(primary_key = True)
    name = models.CharField(max_length=255, null=False,unique=True)
    description = models.TextField(null=True)

class ConnectorAud(models.Model):
    id = models.AutoField(primary_key = True)
    ref_connector_id = models.CharField(max_length=255, null=False)
    name = models.CharField(max_length=255, null=False,unique=True)
    description = models.TextField(null=True)

@receiver(post_save, sender=Connector)
def create_connector_audit_trail(sender, **kwargs):
    connector = ConnectorAud(
            ref_connector_id = kwargs.get('connector_id'),
            name        =   kwargs.get('name'),
            description =   kwargs.get('description',''),
    )
connector.save()

这会导致Connector（）在运行connector.save（）时运行两次

如何解决这个问题？

Answer 1

首先，您应该为dispatch_uid装饰器添加具有唯一名称的@receiver，以避免重复信号（例如，当您多次导入带有信号的文件时，如果唯一{{1，则会多次注册信号不存在）。

每次保存模型时都会调用接收器，如果要在第一次创建连接器时只创建一次dispatch_uid，则应将ConnectorAud param添加到接收器方法中，如下所示：< / p>

created

有了这个，当您编辑并保存@receiver(post_save, sender=Connector, dispatch_uid='create_connector_audit_trail') def create_connector_audit_trail(sender, instance, created, **kwargs): if created: ConnectorAud.objects.create(ref_connector_id=instance.pk, name=instance.name, description=instance.description)时，将不会多次创建Connector。

如何在调用Save后使用Signal

1 个答案: