Task01

一.创建虚拟环境

• python -m venv django_learn （django_learn那里是自己定的环境名字）

• 之前一直用conda管理虚拟环境，没咋用过virtualenv，然后我的powershell之前也设置了默认启动了base环境，然后输入activate命令之后好像没啥反应，试了下pip list，输出一堆东西，看来是没成功切换环境，去问了下Claude，得先conda deactivate，然后再activate就ok了，前面就会显示创建的虚拟环境，出现了django_learn

• powershell和cmd的不同

  • powershell下面是输入 activate命令
  • cmd里面要输入 activate.bat命令

• 习惯用powershell，之后还是用powershell，powershell里面

• 然后安装依赖

  pip install -r requirements.txt

二.创建 Django项目和 APP

我创建的Django项目叫firstProj，APP叫FirstApp

• 首先创建Django项目

  django-admin startproject firstProj 
  

• 产生的结构是

  - firstProj- firstProj(下面有文件）- manage.py
  

• 然后创建APP

  在项目下面新建一个apps文件夹，然后cd进去，输入命令

  django-admin startapp firstApp
  

  

• 去apps.py改个名

  

• 接着去settings.py中注册

  

  增加几个插件

  'rest_framework',
  'django_filters',
  'drf_spectacular',
  

  

三.启动！

运行项目先执行数据库迁移相关操作，再启动 django 项目

# 执行数据库迁移相关操作
python manage.py makemigrations
python manage.py migrate
# 启动django
python manage.py runserver

• models.py中可以构建数据表

  # from django.db import modelsfrom django.db.models import *# Create your models here.
  class Test(Model):name = CharField(max_length=100)
  

• 成功启动！

  

四.创建数据表

文档里给的代码不知道为啥报这个错

SystemCheckError: System check identified some issues:ERRORS:firstApp.Goods.category: (fields.E300) Field defines a relation with model 'goods.GoodsCategory', which is either not installed, or is abstract.firstApp.Goods.category: (fields.E307) The field firstApp.Goods.category was declared with a lazy reference to 'goods.goodscategory', but app 'goods' isn't installed.

下面代码经过claude修改,python [manage.py](http://manage.py/) makemigrations和python manage.py migrate成功了

from django.db import modelsclass GoodsCategory(models.Model):name = models.CharField(max_length=64, verbose_name='名称')remark = models.CharField(max_length=256, null=True, blank=True, verbose_name='备注')class Goods(models.Model):number = models.CharField(max_length=32, verbose_name='编号')name = models.CharField(max_length=64, verbose_name='名称')barcode = models.CharField(max_length=32, null=True, blank=True, verbose_name='条码')# 修复代码:category = models.ForeignKey(GoodsCategory, null=True, on_delete=models.SET_NULL, related_name='goods_set', verbose_name='产品分类')spec = models.CharField(max_length=64, null=True, blank=True, verbose_name='规格')shelf_life_days = models.IntegerField(null=True, verbose_name='保质期天数')purchase_price = models.FloatField(default=0, verbose_name='采购价')retail_price = models.FloatField(default=0, verbose_name='零售价')remark = models.CharField(max_length=256, null=True, blank=True, verbose_name='备注')