Django基础-001

 1 from django.contrib import admin
 2 from django.urls import path
 3 from user import views #引入模块
 4 
 5 urlpatterns = [
 6     path(‘admin/‘, admin.site.urls),
 7     path(‘index/‘, views.user_info),
 8     path(‘welcome/‘,views.welcome),
 9     path(‘‘,views.index),#配置url
10 ]

  1 import os
  2 
  3 # Build paths inside the project like this: os.path.join(BASE_DIR, ...)
  4 BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
  5 
  6 
  7 # Quick-start development settings - unsuitable for production
  8 # See https://docs.djangoproject.com/en/2.1/howto/deployment/checklist/
  9 
 10 # SECURITY WARNING: keep the secret key used in production secret!
 11 SECRET_KEY = ‘6ui+975ck&h4o8f9ga!lnz%j7u&se&-%69&-(h(4!-q4n80y9c‘
 12 
 13 # SECURITY WARNING: don‘t run with debug turned on in production!
 14 DEBUG = True
 15 
 16 ALLOWED_HOSTS = []
 17 
 18 
 19 # Application definition
 20 
 21 INSTALLED_APPS = [ #加增加的应用
 22     ‘django.contrib.admin‘,
 23     ‘django.contrib.auth‘,
 24     ‘django.contrib.contenttypes‘,
 25     ‘django.contrib.sessions‘,
 26     ‘django.contrib.messages‘,
 27     ‘django.contrib.staticfiles‘,
 28     ‘user‘,
 29     ‘test_tools‘,
 30     ‘case‘
 31 ]
 32 
 33 MIDDLEWARE = [
 34     ‘django.middleware.security.SecurityMiddleware‘,
 35     ‘django.contrib.sessions.middleware.SessionMiddleware‘,
 36     ‘django.middleware.common.CommonMiddleware‘,
 37     ‘django.middleware.csrf.CsrfViewMiddleware‘,
 38     ‘django.contrib.auth.middleware.AuthenticationMiddleware‘,
 39     ‘django.contrib.messages.middleware.MessageMiddleware‘,
 40     ‘django.middleware.clickjacking.XFrameOptionsMiddleware‘,
 41 ]
 42 
 43 ROOT_URLCONF = ‘sky.urls‘
 44 
 45 TEMPLATES = [
 46     {
 47         ‘BACKEND‘: ‘django.template.backends.django.DjangoTemplates‘,
 48         ‘DIRS‘: [os.path.join(BASE_DIR,‘templates‘)],#指的是Django寻找html的目录
 49         ‘APP_DIRS‘: True,
 50         ‘OPTIONS‘: {
 51             ‘context_processors‘: [
 52                 ‘django.template.context_processors.debug‘,
 53                 ‘django.template.context_processors.request‘,
 54                 ‘django.contrib.auth.context_processors.auth‘,
 55                 ‘django.contrib.messages.context_processors.messages‘,
 56             ],
 57         },
 58     },
 59 ]
 60 
 61 WSGI_APPLICATION = ‘sky.wsgi.application‘
 62 
 63 
 64 # Database
 65 # https://docs.djangoproject.com/en/2.1/ref/settings/#databases
 66 
 67 DATABASES = {
 68     ‘default‘: {
 69         ‘ENGINE‘: ‘django.db.backends.sqlite3‘,
 70         ‘NAME‘: os.path.join(BASE_DIR, ‘db.sqlite3‘),
 71     }
 72 }
 73 
 74 
 75 # Password validation
 76 # https://docs.djangoproject.com/en/2.1/ref/settings/#auth-password-validators
 77 
 78 AUTH_PASSWORD_VALIDATORS = [
 79     {
 80         ‘NAME‘: ‘django.contrib.auth.password_validation.UserAttributeSimilarityValidator‘,
 81     },
 82     {
 83         ‘NAME‘: ‘django.contrib.auth.password_validation.MinimumLengthValidator‘,
 84     },
 85     {
 86         ‘NAME‘: ‘django.contrib.auth.password_validation.CommonPasswordValidator‘,
 87     },
 88     {
 89         ‘NAME‘: ‘django.contrib.auth.password_validation.NumericPasswordValidator‘,
 90     },
 91 ]
 92 
 93 
 94 # Internationalization
 95 # https://docs.djangoproject.com/en/2.1/topics/i18n/
 96 
 97 #LANGUAGE_CODE = ‘en-us‘ #英文
 98 LANGUAGE_CODE = ‘zh-Hans‘#中文
 99 
100 TIME_ZONE = ‘Asia/Shanghai‘#时区
101 
102 USE_I18N = True
103 
104 USE_L10N = True
105 
106 USE_TZ = False#True：往数据库里插数据，用的标准时区的时间
107 
108 
109 # Static files (CSS, JavaScript, Images)
110 # https://docs.djangoproject.com/en/2.1/howto/static-files/
111 
112 STATIC_URL = ‘/static/‘
113 
114 STATICFILES_DIRS = (
115     os.path.join(BASE_DIR,‘static‘),
116 )
117 
118 MEDIA_ROOT = os.path.join(BASE_DIR,‘images‘)#图片的总目录
119 MEDIA_URL = ‘/images/‘

 1 from django.db import models
 2 
 3 # Create your models here.
 4 class Category(models.Model):
 5     name = models.CharField(verbose_name=‘分类名称‘,max_length=20,unique=True)
 6     create_time = models.DateTimeField(verbose_name=‘创建时间‘,auto_now_add=True)
 7     update_time = models.DateTimeField(verbose_name=‘修改时间‘,auto_now=True)
 8     class Meta:
 9         db_table = ‘category‘ #指定表名
10         verbose_name = ‘分类‘
11         verbose_name_plural = verbose_name
12         ordering = [‘-create_time‘,‘name‘] #排序，默认是升序,-是降序

 1 class Article(models.Model):
 2     title = models.CharField(verbose_name=‘标题‘,max_length=50)
 3     content = models.TextField(verbose_name=‘文章内容‘)
 4     category = models.ForeignKey(Category,on_delete=models.DO_NOTHING,db_constraint=False,verbose_name=‘分类‘)
 5     #建外键，on_delete=models.DO_NOTHING：当分类被删除时，文章不被影响
 6     #db_constraint = False:不会在表中建立真实的外键关系
 7 
 8     img = models.ImageField(upload_to=‘article‘,verbose_name=‘文章图片‘,blank=True)#图片存放的文件夹
 9     create_time = models.DateTimeField(verbose_name=‘创建时间‘, auto_now_add=True)
10     update_time = models.DateTimeField(verbose_name=‘修改时间‘, auto_now=True)
11     class Meta:
12         db_table = ‘article‘ #指定表名
13         verbose_name = ‘文章‘
14         verbose_name_plural = verbose_name
15         ordering = [‘-create_time‘] #排序，默认是升序,-是降序

#外键删除操作模式
    #models.DO_NOTHING:不受任何影响
    #models.CASCADE:关联的数据也会被删除，分类被删除，引用分类的文章也会被删除
    #models.SET:传入一个方法名，用方法返回值
    #models.SET_DEFAULT：删除了，设置为默认值，要该字段有默认值
    #models.SET_NULL：删除了，直接设置为空，要该字段可为空
    #models.PROTECT#受保护，不能删除，只要这个分类下有文章，就不能删除这个分类

 1 from django.http import HttpResponse
 2 from django.shortcuts import render
 3 from . import models
 4 
 5 # Create your views here.
 6 
 7 def user_info(request):
 8     s = ‘你好‘
 9     return HttpResponse(s)#返回的是字符串
10 
11 
12 def welcome(request):
13     username = ‘谢谢啦dddd‘
14     # f = open(‘G:\\pythonWorkspace\\day018\\sky\\templates\\welcome.html‘,encoding=‘utf-8‘)
15     # content = f.read()
16     # new_content = content.replace(‘{{ uname }}‘,username)
17     # return HttpResponse(new_content)
18     # render 就等于上面的一系列操作
19     return render(request,‘welcome.html‘,{‘uname‘:username})
20 
21 
22 def index(request):
23     categories = models.Category.objects.all()
24     articles = models.Article.objects.all()
25     return render(request,‘index.html‘,{‘categories‘:categories,‘articles‘:articles})

1 #第一种方式：增加
2 category = models.Category(name=‘mysql‘)
3 category.save()
4 
5 #第二种方式：增加
6 models.Category.objects.create(name=‘心情日记‘)

1 #修改
2 c1 = models.Category.objects.get(id=1)
3 c1.name = ‘Java‘
4 c1.save()#单个数据修改
5 
6 #多个数据修改
7 q = models.Category.objects.filter(name=‘python‘)
8 q.update(name=‘Python1‘)

 1 #查询
 2 #只能返回一条数据,如果返回多条数据会报错
 3 #如果指定的条件查询不到数据，也会报错
 4 c1 = models.Category.objects.get(name=‘linux‘,id=2)
 5 
 6 #可以返回多条数据，返回结果为list,如果查询不到结果，则返回空
 7 query_set = models.Category.objects.filter(name=‘python‘,id=8)
 8 print(query_set.first().name)
 9 print(query_set[1])
10 print(query_set)
11 
12 #查询所有的数据
13 categories = models.Category.objects.all()

1 #删除
2 #单条数据删除
3 c1 = models.Category.objects.get(id=1)
4 c1.delete()
5 
6 #多条数据删除
7 q = models.Category.objects.filter(name=‘Python1‘)
8 q.delete()