定义数据模型&访问数据库
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定义数据模型
一、Django定义数据模型在App中的models.py文件，数据库的表名称以类的形式来定义：
[root@133 web]# cd /opt/python/django/web/blog/
[root@133 blog]# vim models.py
from django.db import models
# Create your models here.
class Host(models.Model):
hostname = models.CharField(max_length = 50)
ip = models.IPAddressField()二、查看模型的语法和逻辑是否正确：python manage.py validate , 0 errors 没有语法错误
[root@133 blog]# cd /opt/python/django/web
[root@133 web]# ls
blog db.sqlite3 manage.py web
[root@133 web]# python manage.py validate
0 errors found三、管理数据库
初始化数据模型到数据库：python manage.py syncdb (默认使用的slqite数据库，在setting.py可以看到)
[root@133 web]# cd /opt/python/django/web/web/
[root@133 web]# vim settings.py
import os
BASE_DIR = os.path.dirname(os.path.dirname(__file__))#base_dir是seting.py的上级目录的上级目录：/opt/python/django/web/
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
}
}
前提是安装sqlite
[root@133 web]# cd /opt/python/django/web/
[root@133 web]# python manage.py dbshell
SQLite version 3.6.20
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite> .tables
sqlite> .exit
#后台演示同步数据库的时候数据库的创建过程，
[root@133 web]# python manage.py sqlall blog
BEGIN;
CREATE TABLE "blog_host" (
"id" integer NOT NULL PRIMARY KEY,
"hostname" varchar(50) NOT NULL,
"ip" char(15) NOT NULL
)
;
COMMIT;
#同步数据库，会创建表blog_host，创建管理用户
[root@133 web]# 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_host
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'): root #创建管理用户
Email address: david-dai@zamplus.com ＃输入管理用户的邮箱
Password: #输入管理用户的密码
Password (again):
Superuser created successfully.
Installing custom SQL ...
Installing indexes ...
Installed 0 object(s) from 0 fixture(s)
[root@133 web]# ll
总用量 48
drwxr-xr-x 3 root root 4096 1月 3 09:50 blog
-rw-r--r-- 1 root root 34816 1月 3 10:12 db.sqlite3 #大小不为0
-rwxr-xr-x 1 root root 246 1月 1 23:11 manage.py
drwxr-xr-x 2 root root 4096 1月 3 10:02 web查看数据库
方法一：通过admin的页面查看数据库
1、启动django
[root@133 web]# nohup python manage.py runserver 11.65.140.13:8080 &2、在chrome浏览器中访问：输入用户名root和密码，默认是看不到数据库，需要把表注册到admin.py中，admin才能识别
[root@133 blog]# cd /opt/python/django/web/blog/
[root@133 blog]# vim admin.py
from django.contrib import admin
from blog.models import Host ＃加载app应用models
# Register your models here.
class HostAdmin(admin.ModelAdmin):
list_display = ['hostname', 'ip'] #固定属性，类似表中的字段
admin.site.register(Host,HostAdmin) ＃注册两个表，
刷新网页，多了一个host列，点击增加一个host，输入主机名和IP，点击保存，多了一个主机，可以查看
方法二：命令行方式登录查看数据库
[root@133 blog]# cd /opt/python/django/web/
[root@133 web]# ll
总用量 52
drwxr-xr-x 3 root root 4096 1月 3 10:28 blog
-rw-r--r-- 1 root root 34816 1月 3 10:32 db.sqlite3
-rwxr-xr-x 1 root root 246 1月 1 23:11 manage.py
-rw------- 1 root root 2125 1月 3 10:37 nohup.out
drwxr-xr-x 2 root root 4096 1月 3 10:02 web
[root@133 web]# sqlite3 db.sqlite3
SQLite version 3.6.20
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite> .tables
auth_group auth_user_user_permissions
auth_group_permissions blog_host
auth_permission django_admin_log
auth_user django_content_type
auth_user_groups django_session
sqlite> select * from blog_host;
1|132|112.65.140.132
sqlite>.exit
[root@133 web]# python manage.py dbshell
sqlite> .tables
auth_group auth_user_user_permissions
auth_group_permissions blog_host
auth_permission django_admin_log
auth_user django_content_type
auth_user_groups django_session
sqlite> select * from blog_host;
1|132|112.65.140.132访问数据库（一）
1、命令行的交互式方法（类似ipython登陆）：
＃命令行交互式登录
[root@133 web]# python manage.py shell
/opt/amos/python2.7/lib/python2.7/site-packages/django/db/backends/sqlite3/base.py:58: RuntimeWarning: SQLite received a naive datetime (2017-01-03 15:11:34.737126) while time zone support is active.
RuntimeWarning)
Python 2.7.3 (default, Jan 1 2017, 21:43:50)
Type "copyright", "credits" or "license" for more information.
IPython 5.1.0 -- An enhanced Interactive Python.
? -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help -> Python's own help system.
object? -> Details about 'object', use 'object??' for extra details.
In [1]: import sys
In [2]: sys.path
Out[2]:
['',
'/opt/python/django/web', ＃项目的路径/opt/python/django/web成为环境变量
……
……
＃导入表
In [3]: from blog.models import Host #blog 包中的modes.py文件，倒入类class：Host
In [5]: Host.objects.all()
Out[5]: [<Host: Host object>] ＃返回是一个列表［］，每个元素是一个class
＃显示数据
In [6]: nodes = Host.objects.all()
In [7]: nodes.values() #查看表中的内容
Out[7]: [{'ip': u'112.65.140.132', 'hostname': u'132', u'id': 1}]
＃增加数据添加一个host
In [8]: Host(hostname='node02',ip='192.168.1.2')
Out[8]: <Host: Host object>
In [9]: n =Host(hostname='node02',ip='192.168.1.2') ＃实例化一个对象
In [10]: n.save() ＃保存n
In [11]: nodes = Host.objects.all()
In [12]: nodes.values()
Out[12]: [{'ip': u'112.65.140.132', 'hostname': u'132', u'id': 1}, {'ip': u'192.168.1.2', 'hostname': u'node02', u'id': 2}]
另一种方法添加一个host
In [13]: n = Host()
In [18]: n.hostname = 'node03'
In [19]: n.ip = '192.168.1.3'
In [20]: n.save() ＃写入表
In [21]: nodes = Host.objects.all()
In [22]: nodes.values()
Out[22]: [{'ip': u'112.65.140.132', 'hostname': u'132', u'id': 1}, {'ip': u'192.168.1.2', 'hostname': u'node02', u'id': 2}, {'ip': u'192.168.1.3', 'hostname': u'node03', u'id': 3}]
浏览器查看多了一个node03
In [23]: n1 = nodes[0]
In [24]: n1.hostname
Out[24]: u'132'
In [25]: n1.ip
Out[25]: u'112.65.140.132'
In [26]: n1.ip = '192.168.1.1' #直接修改n1的ip值
In [29]: n1.save()
浏览器刷新可以看到主机132的ip已经变为192.168.1.1
In [3]: from blog.models import Host
In [4]: nodes = Host.objects.all()
In [5]: nodes.values()
Out[5]: [{'ip': u'192.168.1.1', 'hostname': u'132', u'id': 1}, {'ip': u'192.168.1.2', 'hostname': u'node02', u'id': 2}, {'ip': u'192.168.1.3', 'hostname': u'node03', u'id': 3}]
In [6]: for i in nodes: print i.hostname
132
node02
node03
In [7]: for i in nodes: print i.hostname,i.ip
132 192.168.1.1
node02 192.168.1.2
node03 192.168.1.32、访问数据库二
通过视图文件views.py来访问数据
1、在urls.py文件里定义urls访问路径
[root@133 web]# cd /opt/python/django/web/web
[root@133 web]# vim urls.py
from django.conf.urls import patterns, include, url
from django.contrib import admin
admin.autodiscover()
urlpatterns = patterns('',
# Examples:
# url(r'^$', 'web.views.home', name='home'),
# url(r'^blog/', include('blog.urls')),
url(r'^admin/', include(admin.site.urls)),
url(r'^blog/index/$', 'blog.views.index'),
url(r'^db/$','blog.views.db'), #增加url配置文件
)2、在views.py里定义访问方法
[root@133 web]# cd /opt/python/django/web/blog/
[root@133 blog]# vim views.py
from django.shortcuts import render
from django.http import HttpResponse
from django.template import loader, Context
from blog.models import Host ＃从blog.models导入Host
# Create your views here.
def index(request):
t = loader.get_template('index.html')
c = Context({})
return HttpResponse(t.render(c))
def db(req):
h = Host()
h.hostname = 'nodes04'
h.ip = '192.168.1.4'
h.save()
return HttpResponse('OK')网页访问：http://11.65.140.13:8080/db/ 返回ok
注意：
request或者req是形式参数，形参可以随便定义，不是非得叫request或者req，可以叫abc。
访问数据库（三）／数据库传递post和get
定义API
1、urls.py
2、views.py定义访问方法（API）
[root@133 blog]# vim views.py
from django.shortcuts import render
from django.http import HttpResponse
from django.template import loader, Context
from blog.models import Host
# Create your views here.
def index(request):
t = loader.get_template('index.html')
c = Context({})
return HttpResponse(t.render(c))
def db(req):
h = Host()
h.hostname = 'nodes04'
h.ip = '192.168.1.4'
h.save()
return HttpResponse('OK')
#添加collect方法
def collect(request):
#if request.method == 'POST':
if request.POST:
hostname = request.POST.get('hostname')
ip = request.POST.get('ip')
host = Host()
host.hostname = hostname
host.ip = ip
host.save()
return HttpResponse('OK,OK')
else:
return HttpResponse('not data')
#修改collect转发规则
[root@133 web]# cd /opt/python/django/web/web/
[root@133 web]# vim urls.py
from django.conf.urls import patterns, include, url
from django.contrib import admin
admin.autodiscover()
urlpatterns = patterns('',
# Examples:
# url(r'^$', 'web.views.home', name='home'),
# url(r'^blog/', include('blog.urls')),
url(r'^admin/', include(admin.site.urls)),
url(r'^blog/index/$', 'blog.views.index'),
url(r'^db/$','blog.views.db'),
url(r'^collect/$','blog.views.collect'), ＃增加collect转发规则
)
浏览器访问：
http://11.65.140.13:8080/collect/ 返回：not data
需要修改setting文件，注释中间件，才能使用curl传数据，否则django不识别
[root@133 web]# vim settings.py
# 'django.middleware.csrf.CsrfViewMiddleware',
＃使用－d参数post方法传hostname和ip
[root@133 blog]# curl -d hostname='node05' -d ip='192.168.1.5' http://112.65.140.133:8080/collect/
OK,OK
服务器端会用get方法提取hostname和ip，然后保存。
可以查看到node05通过get方法，先修改配置，然后通过浏览器传递。get方法是明文的，不是很安全
[root@133 blog]# vim views.py
from django.shortcuts import render
from django.http import HttpResponse
from django.template import loader, Context
from blog.models import Host
# Create your views here.
def index(request):
t = loader.get_template('index.html')
c = Context({})
return HttpResponse(t.render(c))
def db(req):
h = Host()
h.hostname = 'nodes04'
h.ip = '192.168.1.4'
h.save()
return HttpResponse('OK')
def collect(request):
#if request.method == 'POST':
if request.POST:
hostname = request.POST.get('hostname')
ip = request.POST.get('ip')
host = Host()
host.hostname = hostname
host.ip = ip
host.save()
return HttpResponse('OK,OK')
elif: request.method == 'GET': ＃定义get方法
hostname = request.GET.get('hostname')
ip = request.GET.get('ip')
host = Host()
host.hostname = hostname
host.ip = ip
host.save()
return HttpResponse('OK...')
else:
return HttpResponse('not data')浏览器访问，指定hostname＝node07，ip＝192.168.1.7：
http://11.65.140.13:8080/collect/?hostname=node07&ip=192.168.1.7
返回：OK...
http://11.65.140.13:8080/admin/blog/host/
发现host07已经存在，使用浏览器的get方法传数据成功，明文，数据量小
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