【django基础】

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发布时间：2019-06-12

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一、MTV模型

Django的MTV分别代表：

Model(模型)：负责业务对象与数据库的对象(ORM)

Template(模版)：负责如何把页面展示给用户

View(视图)：负责业务逻辑，并在适当的时候调用Model和Template

此外，Django还有一个urls分发器，它的作用是将一个个URL的页面请求分发给不同的view处理，view再调用相应的Model和Template

二、django基本命令

下载安装django

pip3 install django

创建一个django project

django-admin.py startproject mysite

当前目录下会生成mysite的工程，目录结构如下：

manage.py ----- Django项目里面的工具，通过它可以调用django shell和数据库等。

settings.py ---- 包含了项目的默认设置，包括数据库信息，调试标志以及其他一些工作的变量。

urls.py ----- 负责把URL模式映射到应用程序。

python manage.py startapp blog

启动django项目

python manage.py runserver 8080

三、请求的生命周期

网站的本质是socket

服务端（网站）

1. 先启动并监听：80端口                            3. 获取请求信息：                    获取请求中的URL                                        根据URL在已经写好的路由关系中进行匹配：                        [                            /login/      login                            /index/      index                        ]                    　　                    def login(request):                                        请求头                        请求体                                                处理请求                                                                        return                             响应内容：                                响应头\r\n\r\n。。。                                                            断开

客户端（浏览器）

2. 发送请求                    - 连接：www.cnblogs.com:80                    - 发送数据：                        GET:                            GET /news/?page=1&xx=11 http1.1\r\n                            host:www.cnblogs.com\r\n                            Accept-Encoding:gzip, deflate, br\r\n                            User-Agent:Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36                            \r\n\r\n                        POST:                            POST /news/?page=1&xx=11 http1.1\r\n                            host:www.cnblogs.com\r\n                            Accept-Encoding:gzip, deflate, br\r\n                            User-Agent:Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36                            \r\n\r\n                            name=alex&pwd=123                4. 接收响应内容                    响应头写到浏览器                    响应体在浏览器上展示                                        断开

四、主机管理案例

1、创建project及app

django-admin.py startproject mysite   #创建project

python manage.py startapp app01   #创建app

python manage.py runserver    #启动

2、修改配置文件

settings.py

INSTALLED_APPS = [    'django.contrib.admin',    'django.contrib.auth',    'django.contrib.contenttypes',    'django.contrib.sessions',    'django.contrib.messages',    'django.contrib.staticfiles',    'app01.apps.App01Config',      #添加app01]

MIDDLEWARE = [    'django.middleware.security.SecurityMiddleware',    'django.contrib.sessions.middleware.SessionMiddleware',    'django.middleware.common.CommonMiddleware',    # 'django.middleware.csrf.CsrfViewMiddleware',     #注释此行    'django.contrib.auth.middleware.AuthenticationMiddleware',    'django.contrib.messages.middleware.MessageMiddleware',    'django.middleware.clickjacking.XFrameOptionsMiddleware',]

TEMPLATES = [    {        'BACKEND': 'django.template.backends.django.DjangoTemplates',        'DIRS': [os.path.join(BASE_DIR, 'templates')]     #添加模板路径        ,        'APP_DIRS': True,        'OPTIONS': {            'context_processors': [                'django.template.context_processors.debug',                'django.template.context_processors.request',                'django.contrib.auth.context_processors.auth',                'django.contrib.messages.context_processors.messages',            ],        },    },]

#数据库 DATABASES = {    'default': {        'ENGINE': 'django.db.backends.sqlite3',        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),    }}

补充

DATABASES = {    'default': {    'ENGINE': 'django.db.backends.mysql',    'NAME':'dbname',    'USER': 'root',    'PASSWORD': 'xxx',    'HOST': '',    'PORT': '',    }}# 由于Django内部连接MySQL时使用的是MySQLdb模块，而python3中还无此模块，所以需要使用pymysql来代替  # 如下设置放置的与project同名的配置的 __init__.py文件中  import pymysqlpymysql.install_as_MySQLdb()

mysql

#静态文件目录STATIC_URL = '/static/'STATICFILES_DIRS = (    os.path.join(BASE_DIR,'static'),)

代码详情

文件路径

"""Django settings for day16 project.Generated by 'django-admin startproject' using Django 1.11.4.For more information on this file, seehttps://docs.djangoproject.com/en/1.11/topics/settings/For the full list of settings and their values, seehttps://docs.djangoproject.com/en/1.11/ref/settings/"""import os# Build paths inside the project like this: os.path.join(BASE_DIR, ...)BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))# Quick-start development settings - unsuitable for production# See https://docs.djangoproject.com/en/1.11/howto/deployment/checklist/# SECURITY WARNING: keep the secret key used in production secret!SECRET_KEY = 'l))&0*l6$aja*lcq8=0-s9u4byl2%alzfsgdxs_&3_qre&=mvw'# SECURITY WARNING: don't run with debug turned on in production!DEBUG = TrueALLOWED_HOSTS = []# Application definitionINSTALLED_APPS = [    'django.contrib.admin',    'django.contrib.auth',    'django.contrib.contenttypes',    'django.contrib.sessions',    'django.contrib.messages',    'django.contrib.staticfiles',    'app01.apps.App01Config',]MIDDLEWARE = [    'django.middleware.security.SecurityMiddleware',    'django.contrib.sessions.middleware.SessionMiddleware',    'django.middleware.common.CommonMiddleware',    # 'django.middleware.csrf.CsrfViewMiddleware',    'django.contrib.auth.middleware.AuthenticationMiddleware',    'django.contrib.messages.middleware.MessageMiddleware',    'django.middleware.clickjacking.XFrameOptionsMiddleware',]ROOT_URLCONF = 'day16.urls'TEMPLATES = [    {        'BACKEND': 'django.template.backends.django.DjangoTemplates',        'DIRS': [os.path.join(BASE_DIR, 'templates')]        ,        'APP_DIRS': True,        'OPTIONS': {            'context_processors': [                'django.template.context_processors.debug',                'django.template.context_processors.request',                'django.contrib.auth.context_processors.auth',                'django.contrib.messages.context_processors.messages',            ],        },    },]WSGI_APPLICATION = 'day16.wsgi.application'# Database# https://docs.djangoproject.com/en/1.11/ref/settings/#databasesDATABASES = {    'default': {        'ENGINE': 'django.db.backends.sqlite3',        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),    }}# Password validation# https://docs.djangoproject.com/en/1.11/ref/settings/#auth-password-validatorsAUTH_PASSWORD_VALIDATORS = [    {        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',    },    {        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',    },    {        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',    },    {        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',    },]# Internationalization# https://docs.djangoproject.com/en/1.11/topics/i18n/LANGUAGE_CODE = 'en-us'TIME_ZONE = 'UTC'USE_I18N = TrueUSE_L10N = TrueUSE_TZ = True# Static files (CSS, JavaScript, Images)# https://docs.djangoproject.com/en/1.11/howto/static-files/STATIC_URL = '/static/'STATICFILES_DIRS = (    os.path.join(BASE_DIR,'static'),)

settings.py

from django.conf.urls import urlfrom django.contrib import adminfrom app01 import viewsurlpatterns = [    url(r'^admin/', admin.site.urls),    url(r'^login/',views.login),    url(r'^index/',views.index),    url(r'^parts/',views.parts),    url(r'^part_add/',views.part_add),    url(r'^part_del/',views.part_del),    url(r'^part_edit/',views.part_edit),]

urls.py

from django.db import models# Create your models here.from django.db import modelsclass UserInfo(models.Model):    id = models.AutoField(primary_key=True)    user = models.CharField(max_length=32)    pwd = models.CharField(max_length=64)    age = models.IntegerField()class Department(models.Model):    id = models.AutoField(primary_key=True)    title = models.CharField(max_length=32)

models.py

#创建数据库表                python3 manage.py makemigrations                python3 manage.py migrate

from django.shortcuts import render,HttpResponse,redirect# Create your views here.from app01 import models# def test(request):#     # #查询所有用户信息#     # user_list = models.UserInfo.objects.all()#     # for obj in user_list:#     #     print(obj,obj.id,obj.user,obj.pwd)#     ##     # return HttpResponse('123')#     ##     # user_list = models.UserInfo.objects.filter(user='alex',pwd='123').all#     # print(user_list)#     ##     # user = models.UserInfo.objects.filter(user='alex',pwd='123').first()#     # print(user,user.id,user.user,user.pwd)#     return HttpResponse('123')def login(request):    if request.method == "GET":        #打开login.html文件        #找到特殊标记{
     {msg}}        #并将第三个参数中字典总的对应值替换        #将替换完毕的字符串发送给用户浏览器        return render(request,"login.html",{
    'msg':''})    else:        #去请求体中获取数据        username1 = request.POST.get("username")        password1 = request.POST.get("password")        print(username1,password1)        userinfo = models.UserInfo.objects.filter(user=username1,pwd=password1).first()        print(userinfo)        if userinfo:            # return redirect('http://www.baidu.com')            return redirect('/index/')        else:            return render(request,'login.html',{
    'msg':'用户名或密码错误'})        # if user == "alex" and pwd == "123":        #     #在响应头中设置，location：http://www.baidu.com,无响应体        #     return redirect('http://www.baidu.com')        #     #return redirect('/index/')        # else:        #     return render(request,'login.html',{'msg':'用户名或密码错误'})def index(request):    return render(request,'index.html')def parts(request):    depart_list = models.Department.objects.all()    return render(request,'parts.html',{
    'depart_list':depart_list})def part_add(request):    if request.method == 'GET':        return render(request,'part_add.html')    else:        ti = request.POST.get('title')        models.Department.objects.create(title=ti)        return redirect('/parts/')def part_del(request):    nid = request.GET.get('nid')    models.Department.objects.filter(id=nid).delete()    return redirect('/parts/')def part_edit(request):    if request.method == 'GET':        nid = request.GET.get('nid')        obj = models.Department.objects.filter(id=nid).first()        if not obj:            return HttpResponse('写错了，返回吧')        return render(request,'part_edit.html',{
    'obj':obj})    else:        nid = request.GET.get('nid')        title = request.POST.get('title')        models.Department.objects.filter(id=nid).update(title=title)        return redirect('/parts')

views.py

创建如下目录，并将bootstrap导入到plugins下

templates文件夹下创建html文件

    
          Title    欢迎登录
    
              
       业务线管理

index.html

part_add.html

part_edit.html

    
          Title    
          
              
       部门列表
        
                   
        添加        
       
        
       
                         {% for obj in depart_list %}                    
                {% endfor %}            
                                                                           ID                               部门                               操作                          
                    
                                                               {
    { obj.id }}                                   {
    { obj.title }}                                                               编辑                            删除

ID	部门	操作
{ { obj.id }}	{ { obj.title }}	编辑删除

parts.html

数据库截图如下

department表

userinfo表

项目截图

登录界面

登录成功跳转index

parts界面

五、知识补充

1、数据库相关

执行命令：创建数据库表

python3 manage.py makemigrations                python3 manage.py migrate

对应关系

类      ->      表对象    ->      行

数据库操作

表级别：                from django.db import models                # 类对象数据库的表                class UserInfo(models.Model):                    # 字段对应数据库中列                    id = models.AutoField(primary_key=True) # 创建id列，自增，int,主键                    user = models.CharField(max_length=32,null=False)  # varchar(32)                    pwd = models.CharField(max_length=64)                    age = models.IntegerField() # int类型                                    class Department(models.Model):                    """                    部门表                    """                    id = models.AutoField(primary_key=True)                    title = models.CharField(max_length=32)                                            python manage.py makemigrations                python manage.py migrate                             行：                增加：                                        models.UserInfo.objects.create(user="alex",pwd='123',age=18)                                        dic = {
   'user':'alex','pwd':'123',"age":18 }                    models.UserInfo.objects.create(**dic)                                    删除：                                        models.UserInfo.objects.filter(id=12,name='alex').delete()                                        dic = {
   'user':'alex','pwd':'123',"age":18 }                    models.UserInfo.objects.filter(**dic).delete()                                    修改：                                                            models.UserInfo.objects.filter(id=12,name='alex').update(user='11111',pwd='xxxx')                    models.UserInfo.objects.filter(**{...}).update(**{...})                                                        查看：                                        # [obj,obj,obj,....]                    v = models.UserInfo.objects.all()                    # [obj,obj,obj,....]                    v = models.UserInfo.objects.filter(....)                    # obj                    models.UserInfo.objects.filter(....).first()                                        # 获取一个对象；无、多都会报错                    models.UserInfo.objects.get(id=1,name='alex')

2、路由系统

1. 路由系统                         a. url添加起始和终止符                url(r'^example/$', views.example),                url(r'^example/add/$', views.example_add),                        b. 传参，推荐使用二和三                                                                # 方式一                                    # http://127.0.0.1:8000/example_edit/?nid=11&xid=1                                        url(r'^example_edit/$', views.example_edit)                                        def example_edit(request):                        nid = request.GET.get('nid')                        xid = request.GET.get('xid')                        print(nid,xid)                        return HttpResponse('编辑')                                                    # 方式二：                                    # /example_edit/123/111/                    url(r'^example_edit/(\d+)/(\d+)/$', views.example_edit),                                                            def example_edit(request,nid,xid):                        print(nid,xid)                        return HttpResponse('编辑')                                        # 方式三：                                    # /example_edit/123/111/                    url(r'^example_edit/(?P
     
      \d+)/(?P
      
       \d+)/$', views.example_edit),                                                            def example_edit(request,nid,xid):                        print(nid,xid)                        return HttpResponse('编辑')                        c. 路由分发 　　　　　　　　　　　　 　　　　　　　　　　from django.conf.urls import url,include                     s19day17/urls.py                        url(r'^cmdb/', include('cmdb.urls'))                        url(r'^openstack/', include('openstack.urls'))                                                        cmdb/urls.py                         from django.conf.urls import url,include                        from cmdb import views                        urlpatterns = [                            url(r'^host/$', views.host),                        ]                                        openstack/urls.py                         from django.conf.urls import url,include                        from openstack import views                        urlpatterns = [                            url(r'^host/$', views.host),                        ]

3、视图函数

def example_edit(request,nid,xid):                request.method                 request.GET                request.POST                                 return HttpResponse('文本')                return redirect('url')                # 打开模板，读取数据到内存                # {'k1':'v1'}，对模板中的特殊字符进行“渲染”                # 生成不含特殊标签（已经被替换完毕）的字符串                return render(request,'模板路径',{
   'k1':'v1'})

　　　　　　　　def keng(request):

　　　　　　　　　　 return render(request,'keng.html',{'k1':123,'k2':"alex"})

    
         Title    {
   { k1 }}

4、模板语言

tpl.html

    
         Title        {
   { "asdfasdf"|upper }}
    {
   { k1 }}
    #单值    {
   { k2.2 }}
　　　　#索引    {% for item in k2 %}　　　　　　#循环        {
   { item }}    {% endfor %}    {
   { k3.age }}
    {% for k,v in k3.items %}        {
   { k }}  {
   { v }}    {% endfor %}    {% if k1 == 123 %}　　　　#if判断        下课
    {% else %}        放学
    {% endif %}

views.py

def tpl(request):    data_dict = {        'k1': 123123,        'k2':[11,22,33,'alex'],        'k3':{'name':'李杰','age':18}    }    return render(request, 'tpl.html', data_dict)

母版

{% block css %} 程序块{% endblock %} 其余地方为母版内容，继承

    
         Title    
             {% block css %} {% endblock %}    
     
              头部菜单    
     
    
             
      
                   菜单        
      
        
      
                   {% block content %} {% endblock %}        
      
    
     
    {% block js %} {% endblock %}