Django基础,Day2 - 编写urls,views,models
编写views
views:作为MVC中的C,接收用户的输入,调用数据库Model层和业务逻辑Model层,处理后将处理结果渲染到V层中去。
polls/views.py:
from django.http import HttpResponse # Create your views here.
def index(request):
return HttpResponse("Hello, world. You're at the polls index.")
编写urls
urls,程序的入口,支持正则匹配访问url,将访问url映射到views中的具体某个函数中。
为了能调用到上面这个views,我们需要将views.index函数映射到URL中。
我们可以创建一个urls.py 在App目录下。
polls/urls.py:
#!/usr/bin/python
# coding=utf-8 from django.conf.urls import url
from . import views urlpatterns = [
url(r'^$', views.index, name='index'),
]
下一步,我们需要将创建的urls.py 添加到全局urls.py中,如
mysite/urls.py:
from django.conf.urls import url, include
from django.contrib import admin urlpatterns = [
url(r'^polls/', include('polls.urls')),
url(r'^admin/', admin.site.urls),
]
此时,可以通过访问 http://localhost:8000/polls/ 可以调用到所编写的views
编写models
models与数据库操作相关,是django处理数据库的一个特色之处,它包含你的数据库基本字段与数据。通过一系列封装的api可以直接操作数据库。当然,也支持原生sql。
既然models与数据库相关,那么首先需要配置数据库
1、数据库设置,mysite/settings.py:
这里默认使用内置的sqlite3,配置如下:
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
}
}
如果想要改为MYSQL,配置修改如下:
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'NAME': MYSQL_DB,
'USER': MYSQL_USER,
'PASSWORD': MYSQL_PASS,
'HOST': MYSQL_HOST_M,
'PORT': MYSQL_PORT,
}
}
2、初始化数据库数据
在pycharm中,首次使用django相关命令,需要做一些配置。如
配置 python manage.py migrate
配置好后便可运行,运行结果如:
$ python manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, contenttypes, sessions
Running migrations:
Applying contenttypes.0001_initial... OK
Applying auth.0001_initial... OK
Applying admin.0001_initial... OK
Applying admin.0002_logentry_remove_auto_add... OK
Applying contenttypes.0002_remove_content_type_name... OK
Applying auth.0002_alter_permission_name_max_length... OK
Applying auth.0003_alter_user_email_max_length... OK
Applying auth.0004_alter_user_username_opts... OK
Applying auth.0005_alter_user_last_login_null... OK
Applying auth.0006_require_contenttypes_0002... OK
Applying auth.0007_alter_validators_add_error_messages... OK
Applying auth.0008_alter_user_username_max_length... OK
Applying sessions.0001_initial... OK
3、创建models
在本实例中,创建两个models:Questions 和 Choice.
polls/models.py:
from __future__ import unicode_literals from django.db import models # Create your models here. class Question(models.Model):
question_text = models.CharField(max_length=200)
pub_date = models.DateTimeField('date published') class Choice(models.Model):
question = models.ForeignKey(Question, on_delete=models.CASCADE)
choice_text = models.CharField(max_length=200)
votes = models.IntegerField(default=0)
4、激活models
将app包含到project中,我们需要将它的配置类注册到全局配置中的 INSTALLED_APPS 中。它的配置类 PollsConfig 在 polls/apps.py 中,所以它的路径为'polls.apps.PollsConfig'
编辑mysite/settings.py:
INSTALLED_APPS = [
'polls.apps.PollsConfig',
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
]
现在,django已经知道包含了polls app。此时,我们需要告诉django,models已经更改。to create migrations for those changes
$ python manage.py makemigrations polls
makemigrations 命令将会生成一些更新sql语句,同样的,为了在pycharm中容易使用,将其配置如:
运行后,控制台输出如:
然后,重新运行 python manage.py migrate,将会在数据库中创建这些models表。to apply those changes to the database.
$ python manage.py migrate
注意,每次更改models,都必须重新分别执行
$ python manage.py makemigrations
$ python manage.py migrate
增强models
polls/models.py:
from django.db import models
from django.utils.encoding import python_2_unicode_compatible
import datetime
from django.utils import timezone # Create your models here. @python_2_unicode_compatible # only if you need to support Python 2
class Question(models.Model):
question_text = models.CharField(max_length=200)
pub_date = models.DateTimeField('date published') def was_published_recently(self):
return self.pub_date >= timezone.now() - datetime.timedelta(days=1) def __str__(self):
return self.question_text @python_2_unicode_compatible # only if you need to support Python 2
class Choice(models.Model):
question = models.ForeignKey(Question, on_delete=models.CASCADE)
choice_text = models.CharField(max_length=200)
votes = models.IntegerField(default=0) def __str__(self):
return self.choice_text
修改位置:
通过Database API操作数据
进入django shell 环境:
$ python manage.py shell
执行database API:
>>> from polls.models import Question, Choice # Import the model classes we just wrote. # No questions are in the system yet.
>>> Question.objects.all()
<QuerySet []> # Create a new Question.
# Support for time zones is enabled in the default settings file, so
# Django expects a datetime with tzinfo for pub_date. Use timezone.now()
# instead of datetime.datetime.now() and it will do the right thing.
>>> from django.utils import timezone
>>> q = Question(question_text="What's new?", pub_date=timezone.now()) # Save the object into the database. You have to call save() explicitly.
>>> q.save() # Now it has an ID. Note that this might say "1L" instead of "", depending
# on which database you're using. That's no biggie; it just means your
# database backend prefers to return integers as Python long integer
# objects.
>>> q.id # Access model field values via Python attributes.
>>> q.question_text
"What's new?"
>>> q.pub_date
datetime.datetime(, , , , , , , tzinfo=<UTC>) # Change values by changing the attributes, then calling save().
>>> q.question_text = "What's up?"
>>> q.save() # objects.all() displays all the questions in the database.
# Make sure our __str__() addition worked.
>>> Question.objects.all()
<QuerySet [<Question: What's up?>]> # Django provides a rich database lookup API that's entirely driven by
# keyword arguments.
>>> Question.objects.filter(id=)
<QuerySet [<Question: What's up?>]>
>>> Question.objects.filter(question_text__startswith='What')
<QuerySet [<Question: What's up?>]> # Get the question that was published this year.
>>> from django.utils import timezone
>>> current_year = timezone.now().year
>>> Question.objects.get(pub_date__year=current_year)
<Question: What's up?> # Request an ID that doesn't exist, this will raise an exception.
>>> Question.objects.get(id=)
Traceback (most recent call last):
...
DoesNotExist: Question matching query does not exist. # Lookup by a primary key is the most common case, so Django provides a
# shortcut for primary-key exact lookups.
# The following is identical to Question.objects.get(id=).
>>> Question.objects.get(pk=)
<Question: What's up?> # Make sure our custom method worked.
>>> q = Question.objects.get(pk=)
>>> q.was_published_recently()
True # Give the Question a couple of Choices. The create call constructs a new
# Choice object, does the INSERT statement, adds the choice to the set
# of available choices and returns the new Choice object. Django creates
# a set to hold the "other side" of a ForeignKey relation
# (e.g. a question's choice) which can be accessed via the API.
>>> q = Question.objects.get(pk=) # Display any choices from the related object set -- none so far.
>>> q.choice_set.all()
<QuerySet []> # Create three choices.
>>> q.choice_set.create(choice_text='Not much', votes=)
<Choice: Not much>
>>> q.choice_set.create(choice_text='The sky', votes=)
<Choice: The sky>
>>> c = q.choice_set.create(choice_text='Just hacking again', votes=) # Choice objects have API access to their related Question objects.
>>> c.question
<Question: What's up?> # And vice versa: Question objects get access to Choice objects.
>>> q.choice_set.all()
<QuerySet [<Choice: Not much>, <Choice: The sky>, <Choice: Just hacking again>]>
>>> q.choice_set.count() # The API automatically follows relationships as far as you need.
# Use double underscores to separate relationships.
# This works as many levels deep as you want; there's no limit.
# Find all Choices for any question whose pub_date is in this year
# (reusing the 'current_year' variable we created above).
>>> Choice.objects.filter(question__pub_date__year=current_year)
<QuerySet [<Choice: Not much>, <Choice: The sky>, <Choice: Just hacking again>]> # Let's delete one of the choices. Use delete() for that.
>>> c = q.choice_set.filter(choice_text__startswith='Just hacking')
>>> c.delete()
***微信扫一扫,关注“python测试开发圈”,了解更多测试教程!***
Django基础,Day2 - 编写urls,views,models的更多相关文章
- Django基础之路由(urls)层
目录 Django基础之路由(urls)层 无名分组与有名分组 无名分组 有名分组 反向解析 前段解析 后端解析 无名分组反向解析 前段解析 后端解析 有名分组的反向解析 前段解析 后端解析 路由分发 ...
- Django基础(一)_URLconf、Views、template、ORM
一 什么是web框架? 框架,即framework,特指为解决一个开放性问题而设计的具有一定约束性的支撑结构,使用框架可以帮你快速开发特定的系统,简单地说,就是你用别人搭建好的舞台来做表演. 对于所有 ...
- django复习笔记3:urls/views/templates三板斧
0.先看看文件结构 mysite/ mysite/ ├── __pycache__ │ └── manage.cpython-.pyc ├── blog │ ├── __init__.py │ ...
- Django基础知识MTV
Django简介 Django是使用Python编写的一个开源Web框架.可以用它来快速搭建一个高性能的网站. Django也是一个MVC框架.但是在Django中,控制器接受用户输入的部分由框架自行 ...
- Django基础--Django基本命令、路由配置系统(URLconf)、编写视图、Template、数据库与ORM
web框架 框架,即framework,特指为解决一个开放性问题而设计的具有一定约束性的支撑结构. 使用框架可以帮你快速开发特定的系统. 简单地说,就是你用别人搭建好的舞台来做表演. 尝试搭建一个简单 ...
- Django基础之视图(views)层、模板层
目录 Django基础之视图(views)层.模板层 JsonResponse 向前端返回一个json格式字符串的两种方式 重写Django中的json的某个方法 form表单上传文件 FBV与CBV ...
- Django基础之模型(models)层(上)
目录 Django基础之模型(models)层 单表查询 必知必会13条 神奇的双下划线查询 多表查询 外键的字段的增删改查 表与表之间的关联查询 基于双下划线的跨表查询(连表查询) 补充知识 Dja ...
- Django基础之安装配置
安装配置 一 MVC和MTV模式 著名的MVC模式:所谓MVC就是把web应用分为模型(M),控制器(C),视图(V)三层:他们之间以一种插件似的,松耦合的方式连接在一起. 模型负责业务对象与数据库的 ...
- Django基础(一)
Django基础(一) 知识预览 Django基本命令 二 路由配置系统(URLconf) 三 编写视图 四 Template 五 数据库与ORM admin的配置 一 什么是web框架? 框架,即f ...
随机推荐
- 国产方法论之 ReDoIt -- 惟思捷
最近上了PMP课程,感觉受益匪浅,思路有被打开. 很同意一个观点“国人很擅长做事,但是不擅长总结出解决问题的通用框架和方法论”. 为了能提高中小企业生产力我最近成了一个小的软件咨询公司取名“惟思捷”, ...
- Debain下解决sublime无法输入中文
sublime安装的方法在此不做过多介绍,网上有很多中教程的方式.本文描述在已经安装sublime的前提下如何输入中文. 1.保存下面的代码到文件sublime_imfix.c(位于~目录) #inc ...
- ajax请求成功后打开新开窗口(window.open())被拦截的解决方法
问题:今天在做项目时需要在ajax请求成功后打开一个新的窗口,此时遇到浏览拦截了新窗口的问题,尝试在ajax 回调函数中模拟执行 click 或者 submit 等用户行为(trigger('clic ...
- 【推荐】CentOS安装PHP-5.6.4+扩展安装+安全配置+性能配置
注:以下所有操作均在CentOS 6.5 x86_64位系统下完成. #准备工作# 前段时间PHP官方发布了一个重要的安全升级公告,修复了两个unserialize函数的严重漏洞,目前受影响的版本有: ...
- shell 1>&2 2>&1 &>filename重定向的含义和区别
当初在shell中, 看到">&1"和">&2"始终不明白什么意思.经过在网上的搜索得以解惑.其实这是两种输出. 在 shell 程 ...
- SVN“验证位置时发生错误”的解决办法
验证位置时发生错误:“org.tigris.subversion.javahl.ClientException...... 验证位置时发生错误:“org.tigris.subversion.javah ...
- iOS开发常用代码块
遍历可变数组的同时删除数组元素 NSMutableArray *copyArray = [NSMutableArray arrayWithArray:array]; NSString *str1 = ...
- 卷积神经网络(CNN)学习算法之----基于LeNet网络的中文验证码识别
由于公司需要进行了中文验证码的图片识别开发,最近一段时间刚忙完上线,好不容易闲下来就继上篇<基于Windows10 x64+visual Studio2013+Python2.7.12环境下的C ...
- BZOJ 3289: Mato的文件管理[莫队算法 树状数组]
3289: Mato的文件管理 Time Limit: 40 Sec Memory Limit: 128 MBSubmit: 2399 Solved: 988[Submit][Status][Di ...
- GO语言总结(3)——数组和切片
上篇博文简单介绍了一下Go语言的基本类型——GO语言总结(2)——基本类型,本篇博文开始介绍Go语言的数组和切片. 一.数组 与其他大多数语言类似,Go语言的数组也是一个元素类型相同的定长的序列. ( ...