django book querysets

from __future__ import unicode_literals
from django.db import models
from django.contrib.auth.models import User

# Create your models here.

class Host(models.Model):
    hostname=models.CharField(max_length=64)
    ip=models.GenericIPAddressField(unique=True)
    port=models.IntegerField(default=80)
    system_type_choices=(
        ('linux','LINUX'),
        ('Win64','WIN64'),
    )
    system_type=models.CharField(choices=system_type_choices,max_length=64)
    enable = models.BooleanField(default=True)
    create_date = models.DateTimeField()
    online_date = models.DateTimeField(auto_now_add=True)
    groups=models.ManyToManyField('HostGroup')
    idc = models.ForeignKey('IDC'    )

    def __unicode__(self):
        return self.hostname

class IDC(models.Model):
    name = models.CharField(max_length=64,unique=True)
    def __unicode__(self):
        return  self.name

class HostGroup(models.Model):
    name = models.CharField(max_length=64,unique=True)
    def __unicode__(self):
        return self.name

class UserProfile(models.Model):
    user = models.OneToOneField(User)
    name = models.CharField(max_length=64,unique=True)
    host_groups = models.ManyToManyField('HostGroup',blank=True,null=True)
    hosts= models.ManyToManyField('Host',blank=True,null=True)

模糊查询，contains是包含
models.Host.objects.filter(system_type='LINUX',hostname__contains='o')
结果是一个列表  [<Host: localhost>, <Host: ubuntu>, <Host: jindie>]

精确查询，如果有出现多个，结果将报错
models.Host.objects.get(system_type='LINUX',hostname__contains='o')

id大于1的查询
models.Host.objects.filter(id__gt=1)

id in 列表查询
models.Host.objects.filter(id__in=[1,2,3,4,5])


创建第一种方法：models.Host.objects.create
import datetime
datetime.datetime.now()

(1) 写入数据库除了多对对
models.Host.objects.create(
    hostname = 'OA',
    ip = '1.1.1.5',
    port = 80,
    system_type = 'WIN64',
    idc_id =1,  #或者  idc = models.IDC.objects.get(name='万达机房')
    create_date = datetime.datetime.now(),
    online_date = datetime.datetime.now(),
)
（2） 查询刚插入的数据信息（实例）
h = models.Host.objects.get(hostname='OA')
（3） 查询多对多表的所有数据（实例）
all_groups = models.HostGroup.objects.all()
（4）把groups表的数据插入到Host表
h.groups.add(*[i.id for i in  all_groups])

#删除  h.groups.remove(*[i.id for i in  all_groups])

#可以传入字典 h.groups.add(**{'a':1,'b':2})

####################################################
创建的第二种方法，不查找，直接添加，models.Host

(1)
h = models.Host(
    hostname = 'OA',
    ip = '1.1.1.5',
    port = 80,
    system_type = 'WIN64',
    idc_id =1, 
    create_date = datetime.datetime.now(),
)
(2)
h.save()

(3)
all_groups = models.HostGroup.objects.all()

(4)
h.groups.add(*[i.id for i in  all_groups])



##############################################
update
h.hostname = 'feng'
h.save

models.Host.objects.filter().update(port=11111)

##############################################
delete
models.Host.objects.filter(hostname='OA').delete()

#################################################

跨表查询，从用户表查询
a = models.UserProfile.objects.last()
a.host_groups.select_related()
a.hosts_select_related()

####################################

判断用户是否登陆成功后，返回{{request.user}}
{% if request.user.is_authenticated %}
        {{request.user}}
{%else%}    
        <a href="/login">退出</a>

html编写

<div>
    {{ request.user.userprofile.hosts.select_related }}
    <ul>
    {% for group in request.user.userprofile.host_groups.select_related %}
       <li>{{ group.name }}</li>
        <ul>
        {% for host in group.host_set.select_related %}
            <li>{{ host.hostname }}----->{{ host.ip }}---{{ host.idc.name }}</li>
        {% endfor %}
        </ul>
    {% endfor %}
    </ul>

###############################

views

#!/usr/bin/env python
#_*_ coding:utf-8 _*_
from django.shortcuts import render,redirect,HttpResponse,HttpResponseRedirect
from django.template.context import RequestContext
from django.contrib.auth import authenticate,login,logout
from django.contrib.auth.decorators import login_required  #装饰器，不登陆，不能访问其他页面
import models

@login_required()
def host(request):
    return  render(request,'host.html')


def acc_login(request):
    ret = {'status':""}
    if request.method == 'POST':
        print request.POST
        username = request.POST.get('username',None)
        password= request.POST.get('password',None)
        user = authenticate(username=username,password=password)#验证用户名，密码
        if user is not None:
            login(request,user)  #如果不做这个动作，后台login还是没有登陆的，其他页面不能访问，其实就是差一个session
            return HttpResponseRedirect('/')
        else:
            ret['status']='用户名或者密码错误'
            return render(request, 'login.html', ret)
    else:
        return render(request,'login.html')
@login_required()
def index(request):
    return render(request,'index.html')

@login_required()
def asset(request):
    return  render(request,'asset.html')

@login_required()
def acc_logout(request):
    logout(request)
    return  HttpResponseRedirect('login.html')