Django1.10文檔學習筆記二

建立應用

1 建立project

Django-admin startproject mysite

自動建立目錄結構:

mysite/    #項目容器

    Manage.py    #命令行工具

    mysite/   #項目文件

        __init__.py   #定義包的空文件

        Settings.py   #配置文件

        Urls.py  #路由文件

        Wsgi.py #提供底層網絡通訊

 

2 啓動服務器

Python manage.py runserver

 

查看運行

http://127.0.0.1:8000/

 

3 建立應用程序

Python manage.py polls

4 編寫視圖

from django.test import TestCase
from django.http import HttpResponse

# Create your tests here.
def index(request):
return HttpResponse('Hello,word!You are at the polls index')

新建urls.py

from django.conf.urls import url
from . import views

urlpatterns = [
    url(r'^$',views.index,name='index')
]

 

修改mysite/urls.py,添加以下內容:

from django.conf.urls import include

urlpatterns = [

url(r'^polls/',include('polls.urls')),

]

 

啓動服務器

Python manage.py runserver

經過瀏覽器查看

http://127.0.0.1:8000/polls/

 

 

5 數據庫安裝

本示例使用的是mysql數據庫.也能夠使用其餘,對應的配置以下:

Sqlite ’django.db.backends.sqlite3’

Postgresql ’django.db.backends.postgresql’,

Mysql ’django.db.backends.mysql’

Oracle ’django.db.backends.oracle’，

,修改mysite/setting.py,

DATABASES = {
'default': {
#sqlite
       # 'ENGINE': 'django.db.backends.sqlite3',
       # 'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),

        #mysql
'ENGINE':'django.db.backends.mysql',#引擎
'NAME':'jkx',#數據庫名
'USER':'root',#用戶名
'PASSWORD':'yue4512138',#密碼
'HOST':'127.0.0.1',#數據庫服務器ip
'PORT':'3306',#端口號
}
}

 

6 建立model模型

Polls/model.py

每一個模型對應數據庫中的一張表

'''
問題
'''
class Question(models.Model):
    question_text=models.CharField(max_length=200)
    pub_date=models.DateTimeField('date published')

'''
選票
'''
class Choice(models.Model):
    question=models.ForeignKey(Question,on_delete=models.CASCADE)
    choice_text=models.CharField(max_length=200)
    votes=models.IntegerField(default=0)

 

7 註冊應用

Mysite/settings.py

INSTALLED_APPS = [
'django.contrib.admin',#admin站點
'django.contrib.auth',#身份話證系統
'django.contrib.contenttypes',#內容類型框架
'django.contrib.sessions',#會話框架
'django.contrib.messages',#消息框架
'django.contrib.staticfiles',#靜態文件管理框架
'polls.apps.PollsConfig'
]

 

 

從新生成模型的數據表結構,爲改動建立遷移記錄

python manage.py makemigrations polls

 

對數據庫進行真正的遷移

Python manage.py sqlmigrate polls 0001

//在不丟失數據的同時,實時動態更新數據庫

python manage.py migrate

 

8 使用api

 

D:\workspace_python\mysite>python manage.py shell

Python 3.6.0b2 (v3.6.0b2:b9fadc7d1c3f, Oct 10 2016, 20:36:51) [MSC v.1900 32 bit (Intel)] on win32

Type "help", "copyright", "credits" or "license" for more information.

(InteractiveConsole)

>>>

>>> import django

>>> django.setup()#重啓django

>>> from polls.models import Question,Choice#導入操做模塊

>>> Question.objects.all()#查詢question列表

<QuerySet []>

>>> from django.utils import timezone#導入模塊

>>> q=Question(question_text="What is your name?",pub_date=timezone.now())#建立question對象

 

>>> q.save()#保存到數據庫中

>>> q.id

1

>>> q.question_text

'What is your name?'

>>> q.pub_date

datetime.datetime(2016, 10, 21, 9, 34, 11, 36818, tzinfo=<UTC>)

>>> q.question_text='what is up?'#修改屬性值

>>> q.save()#保存到數據庫中

>>> Question.objects.all()#查詢問題列表

<QuerySet [<Question: Question object>]>#看不到問題詳細

須要修改model.py

兩個模型中分別添加:

#想使用python2版本時才能使用
from django.utils.encoding import

python_2_unicode_compatible

 

def __str__(self):#python2版本中使用的是__unique__
return self.question_text

 

def __str__(self):
return self.choice_text

 

修改完成後,從新啓動shell

>>> from polls.models import Question,Choice

>>> Question.objects.all()

<QuerySet [<Question: what is up?>]>

 

>>> Question.objects.filter(id=1)

<QuerySet [<Question: what is up?>]>

 

>>> Question.objects.filter(question_text__startswith='what')

<QuerySet [<Question: what is up?>]>

 

>>> from django.utils import timezone

>>> current_year=timezone.now().year

>>> Question.objects.get(pub_date__year=current_year)

<Question: What is your name?>

 

>>> Question.objects.get(id=2)

Traceback (most recent call last):

  File "<console>", line 1, in <module>

  File "D:\Python36\lib\site-packages\django\db\models\manager.py", line 85, in manager_method

    return getattr(self.get_queryset(), name)(*args, **kwargs)

  File "D:\Python36\lib\site-packages\django\db\models\query.py", line 385, in get

    self.model._meta.object_name

polls.models.DoesNotExist: Question matching query does not exist.

 

 

>>> q.choice_set.all()#查詢關係集合

<QuerySet []>

#建立三個choice對象

>>> q.choice_set.create(choice_text='Not much',votes=0)

<Choice: Not much>

>>> q.choice_set.create(choice_text='The sky',votes=0)

<Choice: The sky>

>>> q.choice_set.create(choice_text='Just hacking again',votes=0)

<Choice: Just hacking again>

>>> q.choice_set.all()#查詢choice列表

<QuerySet [<Choice: Not much>, <Choice: The sky>, <Choice: Just hacking again>]>