项目那几步走：先配置setting路径文件、创建数据库、执行数据库迁移命令、配置mysql数据库信息、注册app、注释中间件、pymysql替换mysqldb-配置urls路由-继续视图函数-然后HTML页面展示-HTML里面导入css文件、models配置数据库表、

django使用mysql数据库：

　　首先cmd创建库

1、settings：

"""
Django settings for day42 project.

Generated by 'django-admin startproject' using Django 1.11.26.

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 = 't2#m1=lilserv388oi=m6i=4b7@-lj6@+kg2-_^oa)wdpi5(96'

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

ALLOWED_HOSTS = []

# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',         #系统内置app
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    "app01.apps.App01Config",       #注册app
]

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

ROOT_URLCONF = 'day42.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 = 'day42.wsgi.application'

# Database
# https://docs.djangoproject.com/en/1.11/ref/settings/#databases
#配置数据库信息：

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': "day43",
        'HOST': "127.0.0.1",
        'PORT': 3306,
        'USER': "root",
        'PASSWORD': "123",
    }
}

#默认使用mysqldb的模块 要使用pymysql替换mysqldb
import pymysql
pymysql.install_as_MySQLdb()

# 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/
#配置路径文件：

STATIC_URL = '/static/'

STATICFILES_DIRS = [
    os.path.join(BASE_DIR,'static')
]
2、urls路由：

"""day42 URL Configuration

The `urlpatterns` list routes URLs to views. For more information please see:
    https://docs.djangoproject.com/en/1.11/topics/http/urls/
Examples:
Function views
    1. Add an import:  from my_app import views
    2. Add a URL to urlpatterns:  url(r'^$', views.home, name='home')
Class-based views
    1. Add an import:  from other_app.views import Home
    2. Add a URL to urlpatterns:  url(r'^$', Home.as_view(), name='home')
Including another URLconf
    1. Import the include() function: from django.conf.urls import url, include
    2. Add a URL to urlpatterns:  url(r'^blog/', include('blog.urls'))
"""
from django.conf.urls import url
from django.contrib import admin
from django.shortcuts import HttpResponse, render
from app01 import views
#配置urls路由

urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^index/', views.index),
    url(r'^modal/', views.modal),
    url(r'^login/', views.login),
]
3、views视图函数：

from django.shortcuts import render,HttpResponse

# Create your views here.

def index(request):
    print(request.path_info)
    # return HttpResponse('<h1>index</h1>')
    return render(request, 'index.html')

def modal(request):
    return render(request, 'modal.html')

def login(request):
    return render(request,"login.html")
4、HTML页面展示：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
{#    增加bootstrap样式：#}
    <link rel="stylesheet" href="/static/plugins/bootstrap-3.3.7-dist/css/bootstrap.min.css">
{#    导入css文件：#}
    <link rel="stylesheet" href="/static/css/signin.css">
</head>
<body>

    <div class="container">

      <form class="form-signin">
        <h2 class="form-signin-heading">Please sign in</h2>
        <label for="inputEmail" class="sr-only">Email address</label>
        <input type="email" id="inputEmail" class="form-control" placeholder="Email address" required="" autofocus="">
        <label for="inputPassword" class="sr-only">Password</label>
        <input type="password" id="inputPassword" class="form-control" placeholder="Password" required="">
        <div class="checkbox">
          <label>
            <input type="checkbox" value="remember-me"> Remember me
          </label>
        </div>
        <button class="btn btn-lg btn-primary btn-block" type="submit">Sign in</button>
      </form>

    </div> <!-- /container -->

    <!-- IE10 viewport hack for Surface/desktop Windows 8 bug -->
    <script src="../../assets/js/ie10-viewport-bug-workaround.js"></script>

</body>
</html>
5、导入css文件：

{#    增加bootstrap样式：#}
    <link rel="stylesheet" href="/static/plugins/bootstrap-3.3.7-dist/css/bootstrap.min.css">
{#    导入css文件：#}
    <link rel="stylesheet" href="/static/css/signin.css">
6、models配置数据库表：

from django.db import models

# Create your models here.

#定义User表、username是具体的字段、CharField是可变长的数据类型：
class User(models.Model):
    username = models.CharField(max_length=32)
    password = models.CharField(max_length=32)

执行数据库迁移的命令：
python manage.py makemigrations（检测已经注册的app）

python manage.py migrate（真正的迁移命令：）

database-database source-MY SQL：

app01和表名组合：

双击表名增加数据并提交：

所有的功能通过类操作：

models.类名.objects.all()--获取表里面所有的数据、获取的是列表
结果：<QuerySet [<User: User object>, <User: User object>, <User: User object>]> <class 'django.db.models.query.QuerySet'>

models.User.objects.get(username="alex",)--获取一条数据、获取的是对象、查询不到报错、查询多条数据报错
结果：User object <class 'app01.models.User'>

models.User.objects.filter(username="alex",password="dsb")--过滤获取对象列表
结果：<QuerySet [<User: User object>]> <class 'django.db.models.query.QuerySet'>

obj = models.Publisher.objects.create(name=pub_name)--　　　　创建

models.Publisher.objects.filter(pk=pk).delete() # 对象列表--　　　　删除
models.Publisher.objects.get(pk=pk).delete() # 对象--　　　　 　　 删除

obj.name = pub_name # 内存中修改属性　　　　　　　　　　　　修改
obj.save() # 提交保存

models.Publisher.objects.filter(pk=pk).update(name=pub_name)　　修改