Ubuntu12.04系统上写你的第一个Django1.5应用(一)-环境搭建-数据库,时区,语言,配置
Ubuntu12.04系统下写你的第一个Django1.5应用(一)--环境搭建--数据库,时区,语言,配置
命令行下会看到如下信息:
问,是否创建超级用户,回答'yes'
创建模型层:
NOTE:We’re using this instead of simply typing “python”, becausemanage.py sets theDJANGO_SETTINGS_MODULEenvironment variable, which gives Djangothe Python import path to yoursettings.py file.
系统:Ubuntu12.04
Django 版本:1.5
确定环境已经搭建好,命令行中输入:
jiangge@ubuntu:~$ python -c "import django; print(django.get_version())" 1.5
1.5是Django的版本,本文基于1.5写成.
创建一个项目: 在命令行输入:
jiangge@ubuntu:~$ django-admin.py startproject mysite
此命令创建一个一个Django项目,tree一下mysite目录,可以看到:
jiangge@ubuntu:~$ tree mysite
mysite
├── manage.py
└── mysite
├── __init__.py
├── settings.py
├── urls.py
└── wsgi.py
1 directory, 5 files
启动开发者服务器:
切换到外面的mysite目录(Change into the outer mysite directory),然后在命令行输入:
jiangge@ubuntu:~$ cd mysite
jiangge@ubuntu:~/mysite$ python manage.py runserver
会看到命令行有如下信息,则表示启动成功:
Validating models...
0 errors found
March 09, 2013 - 22:48:24
Django version 1.5, using settings 'mysite.settings'
Development server is running at http://127.0.0.1:8000/
Quit the server with CONTROL-C.
在浏览器中输入:
http://127.0.0.1:8000/
数据库配置:
编辑mysite目录下的settings.py文件
jiangge@ubuntu:~/mysite$ vim mysite/settings.py
填写数据库引荐,数据库名,用户名,密码,主机,端口号:
默认已经创建数据库:
mysql>CREATE DATABASE mysite DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci;
12 DATABASES = {
13 'default': {
14 'ENGINE': 'django.db.backends.mysql', # Add 'postgresql_psycopg2', 'mysql', 'sqlite3' or 'oracle'.
15 'NAME': 'mysite', #mysql> CREATE DATABASE mysite DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci;
17 'USER': 'root',
18 'PASSWORD': '123456',
19 'HOST': '', # Empty for localhost through domain sockets or '127.0.0.1' for localhost through TCP.
20 'PORT': '', # Set to empty string for default.
21 }
22 }
设置时区和语言:
编辑mysite目录下的settings.py文件
jiangge@ubuntu:~/mysite$ vim mysite/settings.py
TIME_ZONE = 'Asia/Shanghai' #PRC
LANGUAGE_CODE = 'zh-cn' #Simplified Chinese
创建数据库的表结构:
jiangge@ubuntu:~/mysite$ python manage.py syncdb
命令行下会看到如下信息:
Creating tables ... Creating table auth_permission Creating table auth_group_permissions Creating table auth_group Creating table auth_user_user_permissions Creating table auth_user_groups Creating table auth_user Creating table django_content_type Creating table django_session Creating table django_site 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
问,是否创建超级用户,回答'yes'
根据提示继续填写,用户名,邮箱地址,密码:
Username (leave blank to use u'jiangge'): jiangge E-mail address: 499065469@qq.com Password: Password (again): Superuser created successfully. Installing custom SQL ... Installing indexes ... Installed 0 object(s) from 0 fixture(s)
创建App:
命令行输入
jiangge@ubuntu:~/mysite$ python manage.py startapp polls此命令创建了一个polls目录,看下此目录下的文件:
jiangge@ubuntu:~/mysite$ ls manage.py mysite polls jiangge@ubuntu:~/mysite$ tree polls/ polls/ ├── __init__.py ├── models.py ├── tests.py └── views.py 0 directories, 4 files
创建模型层:
编辑polls/models.py文件,写入以下内容:
from django.db import models
class Poll(models.Model):
question = models.CharField(max_length=200)
pub_date = models.DateTimeField('date published')
class Choice(models.Model):
poll = models.ForeignKey(Poll)
choice_text = models.CharField(max_length=200)
votes = models.IntegerField(default=0)
思考:代码中哪些对应表名?哪些对应字段名?
答案:Each model has a number of classvariables, each of which represents a database field in the model.
激活模型(Activating models) :
再次修改settings.py文件,将字符串'polls'添加到INSTALLED_APPS元组当中:
112 INSTALLED_APPS = ( 113 'django.contrib.auth', 114 'django.contrib.contenttypes', 115 'django.contrib.sessions', 116 'django.contrib.sites', 117 'django.contrib.messages', 118 'django.contrib.staticfiles', 119 # Uncomment the next line to enable the admin: 120 # 'django.contrib.admin', 121 # Uncomment the next line to enable admin documentation: 122 # 'django.contrib.admindocs', 123 'polls', 124 )
执行如下命令:
jiangge@ubuntu:~/mysite$ python manage.py sql polls
会看到类似以下信息:
BEGIN;
CREATE TABLE `polls_poll` (
`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY,
`question` varchar(200) NOT NULL,
`pub_date` datetime NOT NULL
)
;
CREATE TABLE `polls_choice` (
`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY,
`poll_id` integer NOT NULL,
`choice_text` varchar(200) NOT NULL,
`votes` integer NOT NULL
)
;
ALTER TABLE `polls_choice` ADD CONSTRAINT `poll_id_refs_id_3aa09835` FOREIGN KEY (`poll_id`) REFERENCES `polls_poll` (`id`);
COMMIT;
NOTE:The sql commanddoesn’t actually run the SQLin your database -it just prints it to the screen so that you can see what SQL Django thinksis required.
If you’re interested, also run the following commands:
- pythonmanage.pyvalidate– Checks for any errorsin the construction of your models.
- pythonmanage.pysqlcustompolls – Outputs anycustom SQL statements (such as table modifications orconstraints) that are defined for the application.
- pythonmanage.pysqlclearpolls – Outputs thenecessaryDROPTABLE statements for this app, according to whichtables already exist in your database (if any).
- pythonmanage.pysqlindexespolls – Outputs theCREATEINDEX statements for this app.
- pythonmanage.pysqlallpolls – A combination of allthe SQL from thesql,sqlcustom, andsqlindexes commands.
python manage.py syncdb
NOTE: syncdb can be called as often as you like, and it will only evercreate the tables that don’t exist.
使用Django API:
命令行中输入:
python manage.py shell
NOTE:We’re using this instead of simply typing “python”, becausemanage.py sets theDJANGO_SETTINGS_MODULEenvironment variable, which gives Djangothe Python import path to yoursettings.py file.
In [3]: from polls.models import Poll, Choice In [4]: Poll.objects.all() Out[4]: [] In [5]: from django.utils import timezone In [6]: p = Poll(question="What's new?", pub_date=timezone.now()) In [7]: p.save() In [8]: p.id Out[8]: 1L In [9]: p.question Out[9]: "What's new?" In [10]: p.pub_date Out[10]: datetime.datetime(2013, 3, 10, 15, 2, 34, 203868, tzinfo=<UTC>) In [11]: p.question = "What's up?" In [12]: p.save() In [13]: Poll. Poll.DoesNotExist Poll.get_previous_by_pub_date Poll.MultipleObjectsReturned Poll.mro Poll.add_to_class Poll.objects Poll.choice_set Poll.pk Poll.clean Poll.prepare_database_save Poll.clean_fields Poll.save Poll.copy_managers Poll.save_base Poll.date_error_message Poll.serializable_value Poll.delete Poll.unique_error_message Poll.full_clean Poll.validate_unique Poll.get_next_by_pub_date In [13]: Poll.objects.all() Out[13]: [<Poll: Poll object>]
在polls/models.py中添加魔术方法:
from django.db import models
# Create your models here.
class Poll(models.Model):
question = models.CharField(max_length=200)
pub_date = models.DateTimeField('date published')
def __unicode__(self):
return self.question
class Choice(models.Model):
poll = models.ForeignKey(Poll)
choice_text = models.CharField(max_length=200)
votes = models.IntegerField(default=0)
def __unicode__(self):
return self.choice_text
In [1]: from polls.models import Poll, Choice In [2]: Poll.objects.all() Out[2]: [<Poll: What's up?>] In [3]: Poll.objects.filter(id=1) Out[3]: [<Poll: What's up?>] In [4]: Poll.objects.filter(question__startswith='What') Out[4]: [<Poll: What's up?>] In [5]: from django.utils import timezone In [6]: current_year = timezone.now().year In [7]: Poll.objects.get(pub_date__year=current_year) Out[7]: <Poll: What's up?> In [8]: Poll.objects.get(id=2) # Request an ID that doesn't exist, this will raise an exception. --------------------------------------- DoesNotExist Traceback (most recent call last) In [9]: Poll.objects.get(pk=1) Out[9]: <Poll: What's up?> In [10]: p = Poll.objects.get(pk=1) # Make sure our custom method worked. In [11]: p.was_published_recently() Out[11]: True In [12]: p = Poll.objects.get(pk=1) In [13]: p.choice_set.all() Out[13]: [] In [14]: p.choice_set.create(choice_text='Not much', votes=0) Out[14]: <Choice: Not much> In [15]: p.choice_set.create(choice_text='The sky', votes=0) Out[15]: <Choice: The sky> In [16]: c = p.choice_set.create(choice_text='Just hacking again', votes=0) In [17]: c.poll Out[17]: <Poll: What's up?> In [18]: p.choice_set.all() Out[18]: [<Choice: Not much>, <Choice: The sky>, <Choice: Just hacking again>] In [19]: p.choice_set.count() Out[19]: 3 In [20]: Choice.objects.filter(poll__pub_date__year=current_year) Out[20]: [<Choice: Not much>, <Choice: The sky>, <Choice: Just hacking again>] In [21]: c = p.choice_set.filter(choice_text__startswith='Just hacking') In [22]:
mysql> desc polls_choice； +-------------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------------+--------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | poll_id | int(11) | NO | MUL | NULL | | | choice_text | varchar(200) | NO | | NULL | | | votes | int(11) | NO | | NULL | | +-------------+--------------+------+-----+---------+----------------+ 4 rows in set (0.00 sec) mysql> desc polls_poll; +----------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +----------+--------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | question | varchar(200) | NO | | NULL | | | pub_date | datetime | NO | | NULL | | +----------+--------------+------+-----+---------+----------------+ 3 rows in set (0.00 sec) mysql>
注:本文由@易枭寒(499065469@qq.com) 根据官方文档写成.转载请注明出处和作者信息.
官方教程地址:https://docs.djangoproject.com/en/1.5/intro/tutorial01/点击打开链接