django笔记-模型数据模板呈现过程记录（多对多关系）
首先,推荐一个网址：http://www.tuicool.com/articles/BfqYz2F，因为这里的比我的要有条理，更有利于各位的理解。
以下仅为为个人一次不完整的笔记：
环境：ubuntu+terminal（前面这几步是上次的重复，可略过）
（PS：这个没有做完，有时间了我重新理一遍，做个调查问卷的例子）
1、建立工程和应用：
root@pc:/home/uu# mkdir work 建立一个文件夹，用于存放工程
root@pc:/home/uu# cd work
root@pc:/home/uu/work# django-admin.py startproject csct06 建立一个工程csct06
root@pc:/home/uu/work# cd csct06/
root@pc:/home/uu/work/csct06# django-admin.py startapp blog 建立一个应用
root@pc:/home/uu/work/csct06# ls
blog csct06 manage.py
2、完成基本设置：
root@pc:/home/uu/work/csct06# vim csct06/settings.py
INSTALLED_APPS = (
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'blog', 注册自己定义的应用
)
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.sqlite3', 这里如果用MySQL或类似数据库，只需要更改这里的相关参数就行了
'NAME': os.path.join(BASE_DIR, 'db.sqlite3'), 参数有6个：'ENGINE'为数据库的类型，'NAME'为使用的数据库名,'USER'为管理员名字
} ‘HOST'一般为localhost，’PORT'为数据库的端口,'PASSWORD'为数据库密码
}
root@pc:/home/uu/work/csct06# vim blog/models.py 这里用于操作数据库
from django.db import models
class Author(models.Model): 生成两个对象：作者和书
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) 作者和书是多对多关系
def __unicode__(self):
return self.name
3、同步数据库：
root@pc:/home/uu/work/csct06# ls
blog csct06 manage.py
root@pc:/home/uu/work/csct06# python manage.py syncdb
。。。。。
Creating tables ...
Creating table django_admin_log
Creating table auth_permission
Creating table auth_group_permissions
Creating table auth_group
Creating table auth_user_groups
Creating table auth_user_user_permissions
Creating table auth_user
Creating table django_content_type
Creating table django_session
Creating table blog_author
Creating table blog_book_authors
Creating table blog_book
You just installed Django's auth system, which means you don't have any superusers defined.
Would you like to create one now? (yes/no): yes
Username (leave blank to use 'root'): uu
Email address: uu@qw.com
Password:
Password (again):
Superuser created successfully.
Installing custom SQL ...
Installing indexes ...
Installed 0 object(s) from 0 fixture(s)
绿色部分为生成的数据库，生成的数据文件为db.sqlite3：
root@pc:/home/uu/work/csct06# ls
blog csct06 db.sqlite3 manage.py
遇到了一个小问题,以前常用mysql的,
root@pc:/home/uu/work/csct06# sqlite3 db.sqlite3
程序“sqlite3”尚未安装。 您可以使用以下命令安装：
apt-get install sqlite3
按照提示做就行了，
#apt-get install sqlite3
。。。
root@pc:/home/uu/work/csct06# sqlite3 db.sqlite3
SQLite version 3.8.2 2013-12-06 14:53:30
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite>
好了，可以操作数据库了。
4、操作数据库：
·1查看生成的数据库表：
sqlite> .tables
auth_group blog_author
auth_group_permissions blog_book
auth_permission blog_book_authors
auth_user django_admin_log
auth_user_groups django_content_type
auth_user_user_permissions django_session
sqlite>
·2进入解释器，对数据进行整理
1）遇到一个小问题：
root@pc:/home/uu/work/csct06# ipython manage.py shell 程序“ipython”尚未安装。 您可以使用以下命令安装： apt-get install ipython 按照操作进行， #apt-get install ipython 出故障了，
root@pc:/home/uu/work/csct06# ipython manage.py shell Usage: manage.py subcommand [options] [args] Options: -v VERBOSITY, --verbosity=VERBOSITY Verbosity level; 0=minimal output, 1=normal output, 2=verbose output, 3=very verbose output --settings=SETTINGS The Python path to a settings module, e.g. "myproject.settings.main". If this isn't provided, the DJANGO_SETTINGS_MODULE environment variable will be used. --pythonpath=PYTHONPATH A directory to add to the Python path, e.g. "/home/djangoprojects/myproject". --traceback Raise on exception --version show program's version number and exit -h, --help show this help message and exit Type 'manage.py help <subcommand>' for help on a specific subcommand. Available subcommands: [auth] changepassword createsuperuser [django] check cleanup compilemessages createcachetable dbshell diffsettings dumpdata flush inspectdb loaddata makemessages runfcgi shell sql sqlall sqlclear sqlcustom sqldropindexes sqlflush sqlindexes sqlinitialdata sqlsequencereset startapp startproject syncdb test testserver validate [sessions] clearsessions [staticfiles] collectstatic findstatic runserver root@pc:/home/uu/work/csct06# ls blog csct06 db.sqlite3 manage.py root@pc:/home/uu/work/csct06# ip ip ipod-read-sysinfo-extended ip6tables ipod-time-sync ip6tables-apply ippfind ip6tables-restore ipptool ip6tables-save iproxy ipcluster iptables ipcmk iptables-apply ipcontroller iptables-restore ipcrm iptables-save ipcs iptables-xml ipengine iptunnel iplogger ipython ipmaddr ipython2.7 root@pc:/home/uu/work/csct06# ipython2.7 manage.py shell /usr/lib/python2.7/dist-packages/IPython/frontend.py:30: UserWarning: The top-level `frontend` package has been deprecated. All its subpackages have been moved to the top `IPython` level. warn("The top-level `frontend` package has been deprecated. " --------------------------------------------------------------------------- MultipleInstanceError Traceback (most recent call last) /usr/lib/python2.7/dist-packages/IPython/utils/py3compat.pyc in execfile(fname, *where) 202 else: 203 filename = fname --> 204 __builtin__.execfile(filename, *where) /home/uu/work/csct06/manage.py in <module>() 8 from django.core.management import execute_from_command_line 9 ---> 10 execute_from_command_line(sys.argv) /usr/local/lib/python2.7/dist-packages/django/core/management/__init__.pyc in execute_from_command_line(argv) 397 """ 398 utility = ManagementUtility(argv) --> 399 utility.execute() /usr/local/lib/python2.7/dist-packages/django/core/management/__init__.pyc in execute(self) 390 sys.stdout.write(self.main_help_text() + '\n') 391 else: --> 392 self.fetch_command(subcommand).run_from_argv(self.argv) 393 394 def execute_from_command_line(argv=None): /usr/local/lib/python2.7/dist-packages/django/core/management/base.pyc in run_from_argv(self, argv) 240 handle_default_options(options) 241 try: --> 242 self.execute(*args, **options.__dict__) 243 except Exception as e: 244 if options.traceback or not isinstance(e, CommandError): /usr/local/lib/python2.7/dist-packages/django/core/management/base.pyc in execute(self, *args, **options) 283 if self.requires_model_validation and not options.get('skip_validation'): 284 self.validate() --> 285 output = self.handle(*args, **options) 286 if output: 287 if self.output_transaction: /usr/local/lib/python2.7/dist-packages/django/core/management/base.pyc in handle(self, *args, **options) 413 if args: 414 raise CommandError("Command doesn't accept any arguments") --> 415 return self.handle_noargs(**options) 416 417 def handle_noargs(self, **options): /usr/local/lib/python2.7/dist-packages/django/core/management/commands/shell.pyc in handle_noargs(self, **options) 79 raise ImportError 80 ---> 81 self.run_shell(shell=interface) 82 except ImportError: 83 import code /usr/local/lib/python2.7/dist-packages/django/core/management/commands/shell.pyc in run_shell(self, shell) 59 for shell in available_shells: 60 try: ---> 61 return getattr(self, shell)() 62 except ImportError: 63 pass /usr/local/lib/python2.7/dist-packages/django/core/management/commands/shell.pyc in ipython(self) 42 for ip in (self._ipython, self._ipython_pre_100, self._ipython_pre_011): 43 try: ---> 44 ip() 45 except ImportError: 46 pass /usr/local/lib/python2.7/dist-packages/django/core/management/commands/shell.pyc in _ipython(self) 36 """Start IPython >= 1.0""" 37 from IPython import start_ipython ---> 38 start_ipython(argv=[]) 39 40 def ipython(self): /usr/lib/python2.7/dist-packages/IPython/__init__.pyc in start_ipython(argv, **kwargs) 116 """ 117 from IPython.terminal.ipapp import launch_new_instance --> 118 return launch_new_instance(argv=argv, **kwargs) 119 120 def start_kernel(argv=None, **kwargs): /usr/lib/python2.7/dist-packages/IPython/config/application.pyc in launch_instance(cls, argv, **kwargs) 542 """ 543 try: --> 544 app = cls.instance(**kwargs) 545 app.initialize(argv) 546 app.start() /usr/lib/python2.7/dist-packages/IPython/config/configurable.pyc in instance(cls, *args, **kwargs) 358 raise MultipleInstanceError( 359 'Multiple incompatible subclass instances of ' --> 360 '%s are being created.' % cls.__name__ 361 ) 362 MultipleInstanceError: Multiple incompatible subclass instances of TerminalIPythonApp are being created.
命令出错了，因该是以下命令：
# python manage.py shell
创建四个作者：
root@pc:/home/uu/work/csct06# python manage.py shell Python 2.7.6 (default, Mar 22 2014, 22:59:56) 。。。。 下面开始执行操作： In [1]: from blog.models import Author,Book In [2]: Author.objects.create(name='Tom1') 用create方法插入数据 Out[2]: <Author: Tom1> In [3]: Author.objects.create(name='Tom2') Out[3]: <Author: Tom2> In [4]: Author.objects.create(name='Bob1') Out[4]: <Author: Bob1> In [5]: Author.objects.create(name='Bob2') Out[5]: <Author: Bob2>
In [8]: auhtors = Author.objects.all() 这里出错了 In [9]: authors --------------------------------------------------------------------------- NameError Traceback (most recent call last) <ipython-input-9-07dd264ecf4d> in <module>() ----> 1 authors NameError: name 'authors' is not defined 按照下面的步骤走，可以解决
直接查询所有作者： In [11]: Author.objects.all() Out[11]: [<Author: Tom1>, <Author: Tom2>, <Author: Bob1>, <Author: Bob2>] 通过赋值查询所有结果： In [12]: author = Author.objects.all() In [13]: author Out[13]: [<Author: Tom1>, <Author: Tom2>, <Author: Bob1>, <Author: Bob2>]
In [14]: b1 = Book() 获取b1对象
In [15]: b1.name = 'Java' 添加第一本书:Java
In [16]: b1.save() 用sava方法保存
为书Java添加作者：
In [20]: tom1 = Author.objects.get(name_exact='Tom1')
---------------------------------------------------------------------------
FieldError Traceback (most recent call last)
。。。
name_exact方法出错，处理：
In [21]: tom1 = Author.objects.get(name='Tom1')
In [22]: tom1
Out[22]: <Author: Tom1>
添加第一个作者：
In [23]: b1.authors.add(tom1)
添加成功：
In [24]: b1.authors.all()
Out[24]: [<Author: Tom1>]
添加第二个作者：
In [26]: b1.authors.add(author[2])
In [27]: b1.authors.all()
Out[27]: [<Author: Tom1>, <Author: Bob1>]
第三个作者，注意一下下标：
In [28]: b1.authors.add(author[1])
In [29]: b1.authors.all()
Out[29]: [<Author: Tom1>, <Author: Tom2>, <Author: Bob1>]
删除一个作者，调用remove方法：
In [30]: b1.authors.remove(tom1)
用all方法进行全部查询：
In [31]: b1.authors.all()
Out[31]: [<Author: Tom2>, <Author: Bob1>]
用filter方法进行局部查询：
In [31]: b1.authors.all()
Out[31]: [<Author: Tom2>, <Author: Bob1>]
这里已经删除了Tom1这个作者，所以查询不到：
In [32]: b1.authors.filter(name='Tom1')
Out[32]: []
In [33]: b1.authors.filter(name='Tom2')
Out[33]: [<Author: Tom2>]
In [34]: tom1 tom1对象前面已经获取了 Out[34]: <Author: Tom1> In [35]: tom1.book_set.all() set是一个集合，也可以看成一个对象 Out[35]: [] In [36]: tom1.book_set.add(b1) 同样用add方法为作者添加一本书，就是前面的书Java
In [40]: tom1.book_set.create(name="python") 添加第二本书
Out[40]: <Book: python>
In [41]: tom1.book_set.all() 共为tom1添加了两本书
Out[41]: [<Book: Java>, <Book: python>]
In [42]: book = Book.objects.all() 查看书的集合
In [43]: book
Out[43]: [<Book: Java>, <Book: python>]
In [44]: tom1.book_set.remove(book[0]) 移除一本书
In [45]: tom1.book_set.all()
Out[45]: [<Book: python>]
5、继续上午的编辑，首先，查看上面做的结果
In [2]: from blog.models import Author,Book 首先导入两个对象作者和书 In [4]: authors = Author.objects.all() 赋值 In [5]: authors 间接查询 Out[5]: [<Author: Tom1>, <Author: Tom2>, <Author: Bob1>, <Author: Bob2>] In [6]: a1 = authors[0] 特定查询第一个作者的信息 In [7]: a1.book_set Out[7]: <django.db.models.fields.related.ManyRelatedManager at 0x7f7f46e53c10> In [9]: a1.book_set.all()[0] 详细查看作者a1出版的书的信息 Out[9]: <Book: python> In [11]: for author in Author.objects.all(): 这里通过一个复杂的结构完成类似功能
....: for book in author.book_set.all():
....: print book
....:
python
Java
Java
各种模块学习大全：
6、如何在web中展现
·1、首先，在blog.views.py里将数据库的内容渲染到html中
blog.views.py
#coding=utf-8 from django.shortcuts import render,render_to_response from blog.models import Author,Book 首先导入数据库里的对象 def show_author(req): authors = Author.objects.all() 遍历作者信息 return render_to_response('show_author.html',{'authors':authors}) 将作者信息渲染到模板文件中
·2、然后，在应用blog目录下创建templates用来保存html
root@pc:/home/uu/work/csct06/blog# mkdir templates
·3、其次，在templates里编辑一个show_author.html，
#vim /blog/templates/show_author.html
先输入变量名，看能否运行：
{{authors}}
保存
·4、设置urls.py,添加映射
url(r'^blog/show_author/$','blog.views.show_author'), 保存推出：wq
·5、运行开发服务器
root@pc:/home/uu/work/csct06# python manage.py runserver ...... Django version 1.6.5, using settings 'csct06.settings' Starting development server at http://127.0.0.1:8000/
在浏览器中运行，
·6、初步成功，接下来进一步完善
{%for author in authors%}
<li>{{author}}</li>
{%endfor%} 注意括号哪里是单括号，哪里是双括号
刷新一下，结果如下：
7、再更改：
{%for author in authors%}
<h1>{{author.name}}</h1>
{%endfor%}
结果如下：
·8、遍历书的信息
{%for author in authors%}
<div>
<h1>{{author.name}}</h1> 这里小结一下：变量用双括号：{{变量}}
{%for book in author.book_set.all%} for循环这里用但括号，且要加上%
<li> {{book}}</li>
{%endfor%}
</div>
{%endfor%}
效果如下：
·9、在解释器里继续操作
In [13]: tom1 = Author.objects.filter(name='Tom1') In [14]: tom1 Out[14]: [<Author: Tom1>]http://blog.csdn.net/lcyangcss/article/details/7249961
下面这里出错了，还未解决，整理中。。。。。。
In [22]: tom1.book_set.create(name='django')
。。。。
AttributeError: 'QuerySet' object has no attribute 'book_set'
In [23]: tom1.book_set.create(name="django")
。。。。
AttributeError: 'QuerySet' object has no attribute 'book_set'
