django-JZTXT

1 常用指令

pip install django -i https://pypi.douban.com/simple/ # 使用豆瓣镜像安装 django
django-admin startproject mysite # 创建个人项目
python manage.py runserver # 启动项目
python manage.py startapp polls # 创建投票应用
python manage.py makemigrations # 生成数据库迁移文件
python manage.py migrate # 执行数据库迁移文件
python manage.py createsuperuser # 创建超级账号

2 编写第一个视图

# polls.views

from django.http import HttpResponse


def index(request):
    return HttpResponse("你好，欢迎来到投票网站")

# polls.urls

from django.urls import path

from . import views

urlpatterns = [
    path("", views.index, name="index"),
]

# mysite.urls

from django.contrib import admin
from django.urls import path, include

urlpatterns = [
    path('admin/', admin.site.urls),
    path("polls/", include("polls.urls")),
]

访问：http://127.0.0.1:8000/polls/

3 创建 model 类并生成数据库表

# polls.models

from django.db import models


class Question(models.Model):
    question_text = models.CharField(max_length=200)
    pub_date = models.DateTimeField("date published")


class Choice(models.Model):
    # 每个选项关联到一个问题
    question = models.ForeignKey(Question, on_delete=models.CASCADE)
    choice_text = models.CharField(max_length=200)
    votes = models.IntegerField(default=0)

执行：

python manage.py makemigrations # 生成数据库迁移文件
python manage.py migrate # 执行数据库迁移文件

使用 shell 命令查看效果：

python manage.py shell # 打开shell 窗口
from polls.models import Choice, Question
Question.objects.all()
# <QuerySet []>
 q = Question(question_text="What's new?", pub_date=timezone.now())
q.save()
q.id
# 1
Question.objects.all()
# <QuerySet [<Question: Question object (1)>]>

但是 <QuerySet [<Question: Question object (1)>]>= 好像并没有实际意义，所以可以给 model 加上 __str__ 方法：

class Question(models.Model):
    question_text = models.CharField(max_length=200)
    pub_date = models.DateTimeField("date published")

    def __str__(self):
        return self.question_text

4 创建超级账号

python manage.py createsuperuser

# polls.admin

from django.contrib import admin

from .models import Question

admin.site.register(Question)

再次访问管理页：