Django入门

Django文档：

https://docs.djangoproject.com/en/1.10/ref/

一、简单创建app

1.1 命令行创建project和app。

django-admin startproject HelloWorld

cd HelloWorld

python manage.py startapp app01

1.2 pycharm创建app

2、将app01加入settings并配置url。

3、启动app

python manage.py runserver 8000

二、

生成环境：

settings.py

DEBUG = False

ALLOWED_HOSTS = ["*"]

2.1 配置加载html

 或者通过render()返回html页面。

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def login(request):     # content = open("templates/app01/login.html","r").read()     # return HttpResponse(content)     return render(request,"app01/login.html")

　　

注意html里的加载的css,jq,js用http的方式或配置静态文件的方式引入。

2.2 django将表应用到数据库。

python manage.py makemigration   #根据class创建创建数据库的配置文件

python manage.py migrate　　　　   # 根据配置文件创建数据库表

2.3 django创建后台管理员账户

python manage.py createsuperuser

2.4 路由系统

动态路由，正则表达式： 这个(d+) 会传入news(request,nid)函数。

二级路由

首先创建app01, python manage.py startapp app02

from django.conf.urls import url,include

,在app01目录下的urls.py下配置urls,在app02目录下的urls.py下配置urls

 2.5 数据库操作

数据库连接：

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DATABASES = {     'default': {         'ENGINE': 'django.db.backends.sqlite3',         'NAME': 'day15',         'HOST':'127.0.0.1',         'PORT':'3306',         'USER':'root',         'PASSWORD':'root',     } }

　　

modles.py

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class UserInfo(models.Model):     username = models.CharField(max_length=32)     password = models.CharField(max_length=32)     age = models.IntegerField() # 默认会自动添加自增的id作为主键

一对多，多对多

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class Author(models.Model):     first_name = models.CharField(max_length=32)     last_name = models.CharField(max_length=32)     email = models.EmailField()   class Publisher(models.Model):     name = models.CharField(max_length=64,unique=True)     address = models.CharField(max_length=128)     city = models.CharField(max_length=64)     state_province = models.CharField(max_length=30)     country = models.CharField(max_length=50)     website = models.URLField()   class Book(models.Model):     bookname = models.CharField(max_length=128)     authors = models.ManyToManyField(Author)     publisher = models.ForeignKey(Publisher)     publish_date = models.DateField()

　　

然后，执行python manage.py makemigrations ;  python manage.py migrate

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E:day15>python2 manage.py makemigrations Migrations for 'app01':   app01migrations0002_auto_20160807_2043.py:     - Create model Author     - Create model Book     - Create model Publisher     - Add field publisher to book E:day15>python2 manage.py migrate Operations to perform:   Apply all migrations: admin, app01, auth, contenttypes, sessions Running migrations:   Rendering model states... DONE   Applying app01.0002_auto_20160807_2043... OK

会生成第三张表：

Django后台管理数据库。

首先在app01的admin.py下注册数据库表

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import models # Register your models here. admin.site.register(models.UserInfo) admin.site.register(models.Author) admin.site.register(models.Book) admin.site.register(models.Publisher)

创建后台用户：

 python manage.py createsuperuser

登录后台并操作表：

定制表在后台返回字符串：

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class Author(models.Model):     first_name = models.CharField(max_length=32)     last_name = models.CharField(max_length=32)     email = models.EmailField()     def __unicode__(self):         return "author: %s %s"%(self.first_name,self.last_name)

后台样式：

由于book是需要关联其他标的，所以在新增book数据时，关联字段是不能任意填写的，只能选择：

修改字段：

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1	first_name = models.CharField(max_length=32,null=True)

python manage.py makemigrations,python manage.py migrate

虽然数据库种这个字段可以为空，但是在Gjango后台还是不能以空插入数据：

要以空值插入数据，需要修改类中的表定义：

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first_name = models.CharField(max_length=32,null=True,blank=True) """ blank¶   Field.blank¶ If True, the field is allowed to be blank. Default is False.   Note that this is different than null. null is purely database-related, whereas blank is validation-related. If a field has blank=True, form validation will allow entry of an empty value. If a field has blank=False, the field will be required. """

参考文档：

https://docs.djangoproject.com/en/1.10/ref/models/fields/

增、删、改、查（针对userinfo表）

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def db_h(request):     # 增     # models.UserInfo.objects.create(username="ds",password="123",age=18)     # 删     # models.UserInfo.objects.filter(username='ds').delete()     # 改     # models.UserInfo.objects.filter(age=18).update(age=20)     # models.UserInfo.objects.all().update(age=19)     # 查     userlist_obj = models.UserInfo.objects.all()       users = []     for user in userlist_obj:         users.append(user.username)       userstring = json.dumps(users)     # models.UserInfo.objects.filter(username='ds')     # models.UserInfo.objects.filter(age=18).first()       return HttpResponse(userstring)

　　模糊查找：参见官方文档。

https://docs.djangoproject.com/en/1.10/ref/models/querysets/

https://docs.djangoproject.com/en/1.10/topics/db/queries/   

 对于上面的多对多手动新增书籍：

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E:python27day15>python2 manage.py shell >>> from datatime import datatime >>> p = models.Publisher.object.filter().first() >>> b =  models.Book(bookname="OWASP",publish_date=datetime.now(),publisher=p) >>> b.save() >>> a = models.Author.objects.filter().first() >>> b.authors.add(a) >>> b.authors.remove(a)

　　

数据库取数据，并将数据传入html

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# app01.views def db_h(request):     userlist_obj = models.UserInfo.objects.all()     return render(request,"app01/tables.html",{"li":userlist_obj})   # templates.app01.tables.html         <table>             <tr>                 <th>姓名</th>                 <th>密码</th>                 <th>年龄</th>             </tr>             {% for item in li %}             <tr>                 <td>{{ item.username}}</td>                 <td>{{ item.password }}</td>                 <td>{{ item.age }}</td>             </tr>             {% endfor %}         </table>

　　

2,6 引入静态文件

注意要是列表或元组，

 2.7 数据提交。

对于POST请求需在setttings里把跨站请求注释掉。# 'django.middleware.csrf.CsrfViewMiddleware',

我们可以通过POST和GET方式提交，提交到后台的数据通过request.GET或request.POST方式取得，request,method是提交的方法，值为"POST"或"GET"。

('val:', <QueryDict: {u'username': [u'gg'], u'age': [u'21'], u'password': [u'rr']}>)  ， 这是在后台打印的POST方式的数据。我们可以通过request.POST["username"]获取username的值。

JSON数据转换：

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# 将字典转为JSON格式（字符串）再发送给客户端 response_data_ok = {"status":"ok"} return HttpResponse(json.dumps(response_data_ok))   # 客户端接收JSON格式的字符串后再反转为原来的格式 "success":function(msg1){                             msg = JSON.parse(msg1) }

　　

 未完待续

2.8 Template渲染

基本语法：

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E:day15>python2 manage.py shell Python 2.7.12 (v2.7.12:d33e0cf91556, Jun 27 2016, 15:19:22) [MSC v.1500 32 bit (Intel)] on win32 Type "help", "copyright", "credits" or "license" for more information. (InteractiveConsole) >>> >>> from django.template import Context,Template >>> t = Template("My name is {{name}},I'am {{age}} years old") >>> c = Context({"name":"DS","age":18}) >>> t.render(c) u"My name is DS,I'am 18 years old" >>> for i in [{"name":"DS","age":18},{"name":"lj","age":20}]: ...     print(t.render(Context(i))) ... My name is DS,I'am 18 years old My name is lj,I'am 20 years old >>>   # 深度变量查找1 >>> p = {"name":"ow","age":20} >>> t1 = Template("My name is {{person.name}}") >>> c = Context({'person':p}) >>> t1.render(c) u'My name is ow'     # 深度变量查找2 >>> t = Template("My name is {{item.1}}") >>> c = Context({"item":["ds","lj","cc"]}) >>> t.render(c) u'My name is lj'   # 深度查找3（类） >>> import datetime >>> d = datetime.date(2016,8,7) >>> d.year 2016 >>> t = Template("today is {{i.year}} {{i.month}} {{i.day}}") >>> c = Context({"i":d}) >>> t.render(c) u'today is 2016 8 7'

Template用于模板文件语法：

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{% for item in li %}             <tr>                 <td>{{ item.username}}</td>                 <td>{{ item.password }}</td>                 <td>{{ item.age }}</td>             </tr> {% endfor %}   forloop.counter0 循环计数器 value}divisibleby:"2"  能被2整除

html继承和重写

模板app01/modle.html

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<html> <body> <div>...</div> {% block content %} {% endblock %} </body> </html>

继承和重写app01/admin.html

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{%  extends "app01/modle.html" %}   {% block content %}     <div class="container">         <table class="table table-bordered table-hover ">             <tr>                 <th>姓名</th>                 <th>密码</th>                 <th>年龄</th>             </tr>             {% for item in li %}             <tr>                 <td>{{ item.username}}</td>                 <td>{{ item.password }}</td>                 <td>{{ item.age }}</td>             </tr>             {% endfor %}         </table>     </div> {%  endblock %}

导入

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# weather.html <div> Weather </div>   # login.html {% include "app01/weather.html %}