django 重写update，create，delete方法详解编程语言

话不多说，直接上代码吧：

from django.db import models 
 
from datetime import datetime 
from django.db import models 
# from DjangoUeditor.models import UEditorField 
 
from django.db.models.query import QuerySet 
 
# Create your models here. 
 
# 重写QuerySet 
class CustomQuerySet(QuerySet): 
    def update(self, **kwargs): 
        print('=====================', kwargs) 
        return super().update(**kwargs) 
 
    def create(self, *args, **kwargs): 
        print('==========create') 
        return super().create(*args, **kwargs) 
 
    def delete(self): 
        print('==========delete') 
        return super().delete() 
 
# 重写对象管理类 
class CategoryManager(models.Manager): 
    def get_queryset(self): 
        return CustomQuerySet(self.model, using=self._db) 
 
 
class GoodsCategory(models.Model): 
    """ 
    商品分类 
    """ 
    CATEGORY_TYPE = ( 
        (1, "一级类目"), 
        (2, "二级类目"), 
        (3, "三级类目"), 
    ) 
 
    name = models.CharField('类别名', default="", max_length=30, help_text="类别名") 
    code = models.CharField("类别code", default="", max_length=30, help_text="类别code") 
    desc = models.TextField("类别描述", default="", help_text="类别描述") 
    # 目录树级别 
    category_type = models.IntegerField("类目级别", choices=CATEGORY_TYPE, help_text="类目级别") 
    # 设置models有一个指向自己的外键 
    parent_category = models.ForeignKey("self", on_delete=models.CASCADE, null=True, blank=True, verbose_name="父类目级别", 
                                        help_text="父目录", 
                                        related_name="sub_cat") 
    is_tab = models.BooleanField("是否导航", default=False, help_text="是否导航") 
    add_time = models.DateTimeField("添加时间", default=datetime.now) 
    # 设置对象管理类 
    objects = CategoryManager() 
 
    class Meta: 
        verbose_name = "商品类别" 
        verbose_name_plural = verbose_name 
 
    def __str__(self): 
        return self.name 
 

主要重写了两个类：

1. CategoryManager
2. CustomQuerySet
3. objects = CategoryManager()

测试结果：

In [1]: from test01.models import GoodsCategory 
 
In [2]: GoodsCategory.objects.all() 
Out[2]: <CustomQuerySet [<GoodsCategory: luojun>]> 
 
In [3]: GoodsCategory.objects.all().create(name='123') 
==========create 
 
In [4]: GoodsCategory.objects.all().delete() 
==========delete 
 
In [5]: GoodsCategory.objects.create(name='123') 
==========create 
>>> GoodsCategory.objects.all().update(name='123') 
===================== {'name': '123'} 
1 
 

注:测试的时候没有回调super方法，所以没有返回结果

save 方法需要在模型内重写