Django 详解

简介

Django 最初被设计用于具有快速开发需求的新闻类站点，目的是要实现简单快捷的网站开发。

设计模型

Django 无需数据库就可以使用，它提供了 对象关系映射器 通过此技术，你可以使用 Python 代码来描述数据库结构。

你可以使用强大的 数据-模型语句 来描述你的数据模型，这解决了数年以来在数据库模式中的难题。以下是一个简明的例子：

from django.db import models

class Reporter(models.Model):
    full_name = models.CharField(max_length=70)

    def __str__(self):
        return self.full_name

class Article(models.Model):
    pub_date = models.DateField()
    headline = models.CharField(max_length=200)
    content = models.TextField()
    reporter = models.ForeignKey(Reporter, on_delete=models.CASCADE)

    def __str__(self):
        return self.headline

Django安装

使用pip安装

pip3 install django==3.2

Django基本使用

创建一个Django项目

django-admin startproject huhuhahei

启动项目

python3 manage.py runserver 
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.
January 14, 2023 - 05:52:11
Django version 3.2.16, using settings 'huhuhahei.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CONTROL-C

如果需要监听0.0.0.0 可以在启动的时候指定监听地址 0.0.0.0:8080

网页访问打开这样就证明启动成功了

配置后台页面

访问后台页面

访问报错找不到表 这里我们需要先初始化下数据库

#初始化数据库
python3 manage.py makemigrations 
No changes detected

#创建库表
python3 manage.py migrate 
Operations to perform:
  Apply all migrations: admin, auth, contenttypes, sessions
Running migrations:
  Applying contenttypes.0001_initial... OK
  Applying auth.0001_initial... OK
  Applying admin.0001_initial... OK
  Applying admin.0002_logentry_remove_auto_add... OK
  Applying admin.0003_logentry_add_action_flag_choices... OK
  Applying contenttypes.0002_remove_content_type_name... OK
  Applying auth.0002_alter_permission_name_max_length... OK
  Applying auth.0003_alter_user_email_max_length... OK
  Applying auth.0004_alter_user_username_opts... OK
  Applying auth.0005_alter_user_last_login_null... OK
  Applying auth.0006_require_contenttypes_0002... OK
  Applying auth.0007_alter_validators_add_error_messages... OK
  Applying auth.0008_alter_user_username_max_length... OK
  Applying auth.0009_alter_user_last_name_max_length... OK
  Applying auth.0010_alter_group_name_max_length... OK
  Applying auth.0011_update_proxy_permissions... OK
  Applying auth.0012_alter_user_first_name_max_length... OK
  Applying sessions.0001_initial... OK
  
#创建admin用户
python3 manage.py createsuperuser
Username (leave blank to use 'root'): admin
Email address: admin
Error: Enter a valid email address.
Email address: admin@^C
Operation cancelled.
[root@blog huhuhahei]# python3 manage.py createsuperuser
Username (leave blank to use 'root'): admin
Email address: admin@qq.com
Password: 
Password (again): 
The password is too similar to the username.
This password is too short. It must contain at least 8 characters.
This password is too common.
Bypass password validation and create user anyway? [y/N]: y

再次访问

创建一个应用

python3 manage.py startapp app01

查看文件结构

tree
.
├── app01
│   ├── admin.py
│   ├── apps.py
│   ├── __init__.py
│   ├── migrations
│   │   └── __init__.py
│   ├── models.py
│   ├── tests.py
│   └── views.py
├── db.sqlite3
├── huhuhahei
│   ├── asgi.py
│   ├── __init__.py
│   ├── __pycache__
│   │   ├── __init__.cpython-36.pyc
│   │   ├── settings.cpython-36.pyc
│   │   ├── urls.cpython-36.pyc
│   │   └── wsgi.cpython-36.pyc
│   ├── settings.py
│   ├── urls.py
│   └── wsgi.py
└── manage.py

setting文件注册应用

INSTALLED_APPS = [
    .......
    'app01',
]

创建一个视图的函数

from django.shortcuts import render
from django.http import HttpResponse


# Create your views here.

def index(request):
    return HttpResponse("hello world")

配置url路由修改urls文件

#添加
from app01 import views

urlpatterns = [
    path('admin/', admin.site.urls),
    path('app01/', views.index),
]

访问 http://106.14.172.136:8080/app01/

配置模块

models文件添加

from django.db import models

# Create your models here.
from django.db  import models
PROJECT_TYPE = [
    (0,"app"),
    (1,"web"),
    (2,"其他")
]

class Project(models.Model):
    project_name = models.CharField(max_length=200, blank=False,verbose_name="项目名称")
    project_type = models.SmallIntegerField(blank=False,choices=PROJECT_TYPE,verbose_name="项目类型")
    project_version = models.CharField(max_length=200, blank=False,verbose_name="项目版本")

admin模块添加

from django.contrib import admin

# Register your models here.

from app01.models import Project

admin.site.register(Project)

#初始化数据库
python3 manage.py makemigrations 

#创建库表
python3 manage.py migrate 

访问后台页面
http://106.14.172.136:8080/admin/

点击去可以正常添加我们需要的文本

Django优化

全局优化

admin 文件添加

admin.site.site_header = "平台管理"
admin.site.site_title = "管理后台"

列表优化

class ProjectAdmin(admin.ModelAdmin):
    list_display = ("project_name","project_type","project_version")


admin.site.register(Project, ProjectAdmin)

导航栏优化

class HuhuhaheiConfig(AppConfig):
    default_auto_field = 'django.db.models.BigAutoField'
    name = 'app01'
    verbose_name = "测试平台"