django4基础

#开始步骤

pip install django
django-admin startproject mysite
python manage.py runserver 8000
打开浏览器访问127.0.0.1:8000 

# 新增url

#urls.py
from django.contrib import admin
from django.urls import path
from . import views

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

#mysite目录下新建views.py
from django.shortcuts import render,HttpResponse 

def hello(req):    
    return HttpResponse("hello world!")

 #增加app

python manage.py startapp post
# 生成 mysite/post目录和目录下 admin.py  apps.py  models.py tests.py views.py __init__.py

# mysite/setting.py中INSTALLED_APPS增加’post‘
INSTALLED_APPS = [
     ...
    'post'
]

#post/views.py 
from django.shortcuts import render,HttpResponse 
def index(request):
    return HttpResponse('post/index')


#创建post/urls.py
from django.urls import path
from . import views
urlpatterns = [
    path('index', views.index,name="index"),
]

#mysite/urls.py
urlpatterns = [
    ...
    path('post/', include('post.urls')),
]

 #创立模型

 Django将关系型的表(table)转换成为一个类(class)。而每个记录(record)是该类下的一个对象(object)。我们可以使用基于对象的方法，来操纵关系型的数据库。

#post/models.py
from django.db import models
class Post(models.Model):
    """post"""
    title=models.CharField(max_length=50)
    content=models.CharField(max_length=500)
    create_at=models.DateTimeField(auto_now_add=True)

    def __str__(self):
        """返回模型的字符串表示"""
        return self.title

#命令行执行迁移
python manage.py  makemigrations
python manage.py migrate post 

#post/views.py添加
from  post.models import Post
def lists(request):
    post_list = Post.objects.all()
    post_str  = map(str, post_list)
    return HttpResponse("<p>" + ' '.join(post_str) + "</p>")

def create(request):
    post=Post(title='bb',content='bbbbbbb')
    post.save()
    return HttpResponse("<p>created bb </p>")

#post/urls.py添加
urlpatterns = [
    ...
    path('lists',views.lists,name="lists"),
    path('create',views.create,name="create"),
]