如何防止覆盖其他人修改过的对象

覆盖首先检查最后一个时间戳的save方法:

def save(self):
    if(self.id):
        foo = Foo.objects.get(pk=self.id)
        if(foo.timestamp > self.timestamp):
            raise Exception, "trying to save outdated Foo" 
    super(Foo, self).save()