django Django--Model中的ManyToManyField及页面显示
多对多的模式：
1. 新建项目
命令：django-admin.py startproject csvt06
2.建app
命令：python manage.py startapp blog
3.修改seting.py
数据库选择sqlite3
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.sqlite3', # Add 'postgresql_psycopg2', 'postgresql', 'mysql', 'sqlite3' or 'oracle'.
'NAME': 'csvt', # Or path to database file if using sqlite3.
'USER': '', # Not used with sqlite3.
'PASSWORD': '', # Not used with sqlite3.
'HOST': '', # Set to empty string for localhost. Not used with sqlite3.
'PORT': '', # Set to empty string for default. Not used with sqlite3.
}
}
app打开admin 、添加blog
INSTALLED_APPS = (
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.sites',
'django.contrib.messages',
'django.contrib.staticfiles',
# Uncomment the next line to enable the admin:
'django.contrib.admin',
# Uncomment the next line to enable admin documentation:
# 'django.contrib.admindocs',
'blog',
)
4.在blog下编辑models.py
from django.db import models
# Create your models here.
class Author(models.Model):
name = models.CharField(max_length =30)
def __unicode__(self):
return self.name
class Book(models.Model):
name = models.CharField(max_length =30)
authors = models.ManyToManyField(Author) #创建多对多的关系
def __unicode__(self):
return self.name
5.在命令行执行命令：python manage.py syncdb
表 blog_book_authors 中存放着表blog_book 和表blog_author的关联关系
用户名：km 密码：123456
6.运行交换shell命令：ipython manage.py shell
在交换窗口输入下面值，blog_author表中创建四个数据
from blog.models import Author ,Book
Author.objects.crea
Author.objects.create(name='Alen')
Author.objects.create(name='Ben')
Author.objects.create(name='Carl')
Author.objects.create(name='Dev')
authors = Author.objects.all()
authors
返回四个author的name
bl = Book()
b1.name = 'python book1'
b1.save()
取出Author中的Alen赋值给alen ‘name__exact’相当于sql 中的like
alen = Author.objects.get(name__exact = 'Alen')
alen
添加对应关系表
b1.authors.add(alen)
b1.authors.add(authors[1])
b1.authors.add(authors[2])
b1.authors.add(authors[3])
b1.author.all
删除对应关系表中的authors中的alen元素
b1.authors.remove(alen)
bl.authors.filter(name__exact='Carl')
查看alen属性
alen.book_set.all()
添加对应关系，把alen和b1添加关联
alen.book_set.add(b1)
alen.book_set.all()
alen.book_set.create(name = 'python book2')
alen.book_set.all()
显示[<Book: python book1>,<Book:python book2>]
删除book中的第一个书
alen.book_set.remove(books[0])
shell中循环显示作者和他的书
for author in Author.objects.all():
for book in author.book_set.all():
print book
python book1
python book2
python book1
python book1
python book1
from blog.mobels import Author
alen = Author.objects.filter(name='Alen')
alen
通过shell添加一本书
alen.book_set.create(name='web1 book');
from blog.models import Book
books = Book.objects.all()
books
books[0]
b1 = books[0]
bl.authors.all()
7.在blog中添加views.py
# Create your views here.
from blog.models import Author,Book
from django.shortcuts import render_to_response
def show_author(req):
authors = Author.objects.all()
return render_to_response('show_author.html',{'authors':authors})
def show_book(req):
books = Book.objects.all()
return render_to_response('show_book.html',{'books':books})
8.在项目中添加url.py
from django.conf.urls.defaults import patterns, include, url
# Uncomment the next two lines to enable the admin:
# from django.contrib import admin
# admin.autodiscover()
urlpatterns = patterns('',
# Examples:
# url(r'^$', 'temp.views.home', name='home'),
# url(r'^temp/', include('temp.foo.urls')),
# Uncomment the admin/doc line below to enable admin documentation:
# url(r'^admin/doc/', include('django.contrib.admindocs.urls')),
# Uncomment the next line to enable the admin:
# url(r'^admin/', include(admin.site.urls)),
url(r'^blog/show_author/$','blog.views.show_author'),
url(r'^blog/show_book/$','blog.views.show_book'),
)
9.在blog下建文件夹templates，新建模板文件show_author.html 和show_book.html
show_author.html-----循环显示每个作者的书
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title> New Document </title>
<meta name="Generator" content="EditPlus">
<meta name="Author" content="">
<meta name="Keywords" content="">
<meta name="Description" content="">
</head>
<body>
{% for author in authors%}
<h3>{{author.name}}</h3>
{% for book in author.book_set.all%}
<li>{{book}}</li>
{%endfor%}
{%endfor%}
</body>
</html>
show_book.html----循环每本书的作者
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title> New Document </title>
<meta name="Generator" content="EditPlus">
<meta name="Author" content="">
<meta name="Keywords" content="">
<meta name="Description" content="">
</head>
<body>
{% for book in books%}
<div>
<h1>{{book.name}}</h1>
{% for author in book.authors.all%}
<li>{{author}}</li>
{%endfor%}
</div>
{%endfor%}
</body>
</html>
10.命令行运行自动服务器
命令：python manage.py runserver
访问地址：http://127.0.0.1:8000/blog/show_book/
http://127.0.0.1:8000/blog/show_author/
完成