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Django和模型中的信号post_保存

models signals django

Ekaterina Premudraya · 技术社区 · 7 年前

我有信号功能:

@receiver(post_save, sender=Task)
def my_handler():
    executor = User.objects.filter(user_type='Executer')
    executor.balance += Task.money
    executor.save()

我的功能应该在添加任务后向执行者添加资金。但它会产生如下错误:

Internal Server Error: /api/v1/tasks/
Traceback (most recent call last):
  ...
  File "/home/k/pro/freelance-django/free/lib/python3.5/site-packages/django/db/models/fields/__init__.py", line 1853, in get_prep_value
    return int(value)
ValueError: invalid literal for int() with base 10: 'Executer'
[20/Sep/2017 14:00:30] "POST /api/v1/tasks/ HTTP/1.1" 500 188088

用户类

   from __future__ import unicode_literals

from django.db import models
from django.contrib.auth.models import AbstractUser


class User(AbstractUser):
    CUSTOMER = 1
    EXECUTER = 2

    USER_TYPES = (
        (CUSTOMER, 'Customer'),
        (EXECUTER, 'Executer'),
    )

    user_type = models.IntegerField(choices=USER_TYPES, default=EXECUTER, verbose_name='Ð¢Ð¸Ð¿ Ð¿Ð¾Ð»ÑÐ·Ð¾Ð²Ð°ÑÐµÐ»Ñ')
    balance = models.DecimalField(decimal_places=2, max_digits=7, default=0, verbose_name='ÐÐ°Ð»Ð°Ð½Ñ')


    def __str__(self):
        return self.username

来自任务。型号为:

class Task(models.Model):
    title = models.CharField(max_length=255, verbose_name='ÐÐ°Ð³Ð¾Ð»Ð¾Ð²Ð¾Ðº')
    description = models.CharField(max_length=255, verbose_name='ÐÐ¿Ð¸ÑÐ°Ð½Ð¸Ðµ')
    money = models.DecimalField(max_digits=7, decimal_places=2, default=0, verbose_name='Ð¦ÐµÐ½Ð°')
    assignee = models.ForeignKey('users.User', related_name='assignee', null=True, verbose_name='ÐÑÐ¿Ð¾Ð»Ð½Ð¸ÑÐµÐ»Ñ')
    created_by = models.ForeignKey('users.User', related_name='created_by', verbose_name='ÐÐµÐ¼ Ð±ÑÐ» ÑÐ¾Ð·Ð´Ð°Ð½')

我该怎么做?

1 回复 | 直到 7 年前

Thaian 7 年前

你没有一个但是物体 update() . 最好的选择是使用F表达式,因为它在DB上执行,因此具有良好的性能:

from django.db.models import F    

@receiver(post_save, sender=Task)
def my_handler(sender, instance, **kwargs):
    User.objects.filter(user_type=User.EXECUTER).update(balance=F('balance') + instance.money)

这将更新用户类型为Executer的所有记录,并在一个查询中更新它们的余额。

Django docs update

F expressions

你的 user_type

class User(AbstractUser):
    CUSTOMER = 1
    EXECUTER = 2

    USER_TYPES = (
        (CUSTOMER, 'Customer'),
        (EXECUTER, 'Executer'),
    )

    user_type = models.IntegerField(choices=USER_TYPES, default=EXECUTER, verbose_name='Ð¢Ð¸Ð¿ Ð¿Ð¾Ð»ÑÐ·Ð¾Ð²Ð°ÑÐµÐ»Ñ')
    balance = models.DecimalField(decimal_places=2, max_digits=7, default=0, verbose_name='ÐÐ°Ð»Ð°Ð½Ñ')