Django 初始 实现

pip instal django

查看django版本  python 

import django

django.get_version()

django-admin startproject myapp

You have 18 unapplied migration(s). Your project may not work properly until you apply the migrations for app(s): admin, auth, contenttypes, sessions.
Run 'python manage.py migrate' to apply them.

python mange.py migrate

创建app

python manage.py startapp polls

一个app实现一个具体功能

一个project是配置文件和多个app集合，组成整个站点

一个project包含多个app

一个app属于多个project

 

编写第一个视图 <--> 路由

app中views.py 

from django.http import HttpResponse

def index(request):
    return HttpResponse("这里是liujiangblog.com的投票站点")

 app中urls.py

from django.urls import path

from . import views

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

project中urls添加

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

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

数据库配置

# Database
# https://docs.djangoproject.com/en/3.1/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': BASE_DIR / 'db.sqlite3',
    }
}

启用模型层

app models.py

# polls/models.py

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):
    question = models.ForeignKey(Question, on_delete=models.CASCADE)
    choice_text = models.CharField(max_length=200)
    votes = models.IntegerField(default=0)

模型层定义好了之后，django做两件事

创建数据表结构

创建数据表结构的python访问API

但是，首先要把使用app进去

然后数据库迁移

$ python manage.py makemigrations polls # 为改动创建迁移记录文件

python manage.py migrate # 将操作同步到数据库，也就是执行这个迁移文件

 admin后台管理站点

$ python manage.py createsuperuser

Username: admin

Password: **********
Password (again): *********
Superuser created successfully.
http://127.0.0.1:8000/admin/