【django基础】

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。

  • 在mysite目录下创建应用

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

<!DOCTYPE html><html lang="zh-cn">。。。</html>
                            
            
                    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

                            host:www.cnblogs.com

                            Accept-Encoding:gzip, deflate, br

                            User-Agent:Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36
                            


                        POST:
                            POST /news/?page=1&xx=11 http1.1

                            host:www.cnblogs.com

                            Accept-Encoding:gzip, deflate, br

                            User-Agent:Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36
                            


                            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 pymysql
pymysql.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, see
https://docs.djangoproject.com/en/1.11/topics/settings/

For the full list of settings and their values, see
https://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 = True

ALLOWED_HOSTS = []


# Application definition

INSTALLED_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/#databases

DATABASES = {
    '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-validators

AUTH_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 = True

USE_L10N = True

USE_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 url
from django.contrib import admin
from app01 import views

urlpatterns = [
    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 models

class 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

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <h1>欢迎登录</h1>
    <ul>
        <li><a href="/parts/">业务线管理</a></li>
    </ul>
</body>
</html>
index.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="/static/plugins/bootstrap/css/bootstrap.css">
</head>
<body>

<div style=" 500px;margin: 0 auto;margin-top: 80px;">
    <form class="form-horizontal" action="/login/" method="post">
        <div class="form-group">
            <label for="n1" class="col-sm-2 control-label">用户名</label>
            <div class="col-sm-10">
                <input id="n1" type="text" name="username" class="form-control" placeholder="用户名">
            </div>
        </div>
        <div class="form-group">
            <label for="n2" class="col-sm-2 control-label">密码</label>
            <div class="col-sm-10">
                <input id="n2" type="password" name="password" class="form-control" placeholder="密码">
            </div>
        </div>
        <div class="form-group">
            <div class="col-sm-offset-2 col-sm-10">
                <input type="submit" value="登 录" class="btn btn-primary">{{ msg }}
            </div>
        </div>
    </form>
</div>
</body>
</html>
login.py
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="/static/plugins/bootstrap/css/bootstrap.css">
</head>
<body>
    <div class="container">
        <h1>添加部门</h1>
        <form action="" method="POST">
            <input type="text" name="title">
            <input type="submit" vlaue="添加">
        </form>
    </div>

</body>
</html>
part_add.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="/static/plugins/bootstrap/css/bootstrap.css">
</head>
<body>
    <div class="container">
        <h1>编辑部门</h1>
        <form action="" method="post">
            <div class="form-group">
                <label for="t1">部门名称</label>
                <input type="text" id="'t1" class="form-control" name="title" vlaue="{{ obj.title }}">
            </div>
            <input type="submit" value="修改" class="btn btn-default">
        </form>
    </div>
</body>
</html>
part_edit.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="/static/plugins/bootstrap/css/bootstrap.css">
</head>
<body>
    <div class="container">
        <h1>部门列表</h1>
        <div style="margin: 5px 0">
            <a href="/part_add/" class="btn btn-success"><span class="glyphicon glyphicon-plus" aria-hidden="true"></span>添加</a>
        </div>
        <table class="table table-bordered">
            <thead>
                <tr>
                    <th>ID</th>
                    <th>部门</th>
                    <th>操作</th>
                </tr>
            </thead>
            <tbody>
                {% for obj in depart_list %}
                    <tr>
                        <td>{{ obj.id }}</td>
                        <td>{{ obj.title }}</td>
                        <td>
                            <a href="/part_edit/?nid={{ obj.id }}" class="btn btn-info"><span class="glyphicon glyphicon-cog" aria-hidden="true"></span>编辑</a>
                            <a href="/part_del/?nid={{ obj.id }}" class="btn btn-danger"><span class="glyphicon glyphicon-remove" aria-hidden="true"></span>删除</a>
                        </td>
                    </tr>
                {% endfor %}
            </tbody>
        </table>
    </div>

</body>
</html>
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<xid>d+)/(?P<nid>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"})

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <h1>{{ k1 }}</h1>

    <script>
        alert("{{ k2 }}");
    </script>
</body>
</html>

4、模板语言

tpl.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
        <h1>{{ "asdfasdf"|upper }}</h1>

    <h1>{{ k1 }}</h1>    #单值
    <h1>{{ k2.2 }}</h1>　　　　#索引
    {% for item in k2 %}　　　　　　#循环
        <a href="#">{{ item }}</a>
    {% endfor %}

    <h1>{{ k3.age }}</h1>

    {% for k,v in k3.items %}
        <a href="#">{{ k }}  {{ v }}</a>
    {% endfor %}

    {% if k1 == 123 %}　　　　#if判断
        <h1>下课</h1>
    {% else %}
        <h1>放学</h1>
    {% endif %}

</body>
</html>

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
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="/static/plugins/bootstrap/css/bootstrap.css">
    <style>
        body{
            margin: 0;
        }
    </style>
    {% block css %} {% endblock %}
</head>
<body>
    <div style="height: 48px;background-color: #1b6d85">
        头部菜单
    </div>
    <div>
        <div style="float: left; 20%;background-color: #dddddd;height: 500px;">
            菜单
        </div>
        <div style="float: left; 80%">
            {% block content %} {% endblock %}
        </div>
    </div>

    {% block js %} {% endblock %}
</body>
</html>
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原文地址：https://www.cnblogs.com/smallmars/p/8259358.html