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一、ORM操作进阶
ForeignKey关联
示例models
from django.db import models # Create your models here. class User(models.Model): name = models.CharField(max_length=32) class Host(models.Model): host_name = models.CharField(max_length=32) blong_to = models.ForeignKey("User")
ForeignKey创建数据
models.Host.objects.create(host_name="127.0.0.1",blong_to=models.User.objects.get(id=1))
1、搜索条件使用 __ 连接 2、获取值时使用 . 连接
user_list=models.Host.objects.filter(blong_to__name="lisi") #一对多过滤条件 for item in user_list: print(item.host_name,item.blong_to.name) #取数据，在前端取数据也类似
ForeignKey修改数据
hosts=models.Host.objects.get(host_name="127.0.0.1") users=models.User.objects.get(id=2) hosts.blong_to=users hosts.save()
反向关联查询
user_obj=models.User.objects.get(id=2) print(user_obj.host_set.select_related())
ManyToManyField关联
示例models
class UserInfo(models.Model): name = models.CharField(max_length=32) email = models.CharField(max_length=32) address = models.CharField(max_length=128) class UserGroup(models.Model): caption = models.CharField(max_length=64) user_info = models.ManyToManyField(‘UserInfo‘)
ManyToManyField操作（_set是多对多中的固定搭配）
user_info_obj = models.UserInfo.objects.get(name="zhangsan") user_info_objs = models.UserInfo.objects.all() group_obj = models.UserGroup.objects.get(caption=‘CEO‘) group_objs = models.UserGroup.objects.all() # 添加数据 #group_obj.user_info.add(user_info_obj) #group_obj.user_info.add(*user_info_objs) # #user_info_obj.usergroup_set.add(group_obj) #user_info_obj.usergroup_set.add(*group_objs) # 删除数据 #group_obj.user_info.remove(user_info_obj) #group_obj.user_info.remove(*user_info_objs) # #user_info_obj.usergroup_set.remove(group_obj) #user_info_obj.usergroup_set.remove(*group_objs) # 获取数据 #print group_obj.user_info.all() #print group_obj.user_info.all().filter(id=1) # #print user_info_obj.usergroup_set.all() #print user_info_obj.usergroup_set.all().filter(caption=‘CEO‘)
F 对同一表内不同的字段进行对比查询
class Entry(models.Model): n_comments = models.IntegerField() n_pingbacks = models.IntegerField() rating = models.IntegerField()
from django.db.models import F models.Entry.objects.filter(n_comments__gt=F(‘n_pingbacks‘)) models.Entry.objects.filter(n_comments__gt=F(‘n_pingbacks‘) * 2) models.Entry.objects.filter(rating__lt=F(‘n_comments‘) + F(‘n_pingbacks‘))
批量自增
models.Entry.objects.all().update(n_pingbacks=F(‘n_pingbacks‘) + 1)
Q 构建搜索条件
from django.db.models import Q models.UserInfo.objects.get( Q(name=‘zhangsan‘),Q(email="12345678@qq.com")) #两个都要满足 models.UserInfo.objects.get( Q(name=‘zhangsan‘) | Q(email="12345678@qq.com")) #只需满足一个
models.UserInfo.objects.get( Q(name=‘zhangsan‘),Q(email="12345678@qq.com") | Q(address="abcde"))
二、django 实现分页
实例
#!/usr/bin/env python # -*- coding:utf-8 -*- from django.shortcuts import render,HttpResponse from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger from app01 import models # Create your views here. def stu_login(request): return render(request,"app01/login.html") def stu_home(request): customer_list=models.Customer.objects.all() paginator = Paginator(customer_list, 1) #每页显示条数 page = request.GET.get(‘page‘) try: contacts = paginator.page(page) except PageNotAnInteger: # If page is not an integer, deliver first page. contacts = paginator.page(1) except EmptyPage: # If page is out of range (e.g. 9999), deliver last page of results. contacts = paginator.page(paginator.num_pages) return render(request, "app01/home.html", {"customer_list":contacts})
<div class="pagination"> <nav> <ul class="pagination"> {% if customer_list.has_previous %} <li class=""><a href="?page={{ customer_list.previous_page_number }}" aria-label="Previous"><span aria-hidden="true">«</span></a></li> {% endif %} {% for page_num in customer_list.paginator.page_range %} {% if page_num == customer_list.number %}<!--如果page_num是当前选中的页--> <li class="active"><a href="?page={{ page_num }}">{{ page_num }} <span class="sr-only">(current)</span></a></li> {% else %} <li class=""><a href="?page={{ page_num }}">{{ page_num }} <span class="sr-only">(current)</span></a></li> {% endif %} {% endfor %} {% if customer_list.has_next %} <li class=""><a href="?page={{ customer_list.next_page_number }}" aria-label="Next"><span aria-hidden="true">»</span></a></li> {% endif %} </ul> </nav> </div>
优化：固定页码个数
1、自定义template tags
#!/usr/bin/env python # -*- coding:utf-8 -*- from django import template from django.utils.safestring import mark_safe register = template.Library() @register.simple_tag def custemer_paging(current_page,loop_num): #传入选中页和循环页 num_left=current_page-2 num_right=current_page+2 if loop_num>num_left and loop_num<num_right:#只显示3页 if current_page == loop_num: result=‘‘‘<li class="active"><a href="?page=%s">%s <span class="sr-only">(current)</span></a></li>‘‘‘%(loop_num,loop_num) else: result=‘‘‘<li class=""><a href="?page=%s">%s <span class="sr-only">(current)</span></a></li>‘‘‘%(loop_num,loop_num) return mark_safe(result) result="" return mark_safe(result)
在html开头导入
{% load custemer_tags %}
使用自定义simple_tag
<div class="pagination"> <nav> <ul class="pagination"> {% if customer_list.has_previous %} <li class=""><a href="?page={{ customer_list.previous_page_number }}" aria-label="Previous"><span aria-hidden="true">«</span></a></li> {% endif %} {% for page_num in customer_list.paginator.page_range %} {% custemer_paging customer_list.number page_num %}<!--使用custemer_tags--> {% endfor %} {% if customer_list.has_next %} <li class=""><a href="?page={{ customer_list.next_page_number }}" aria-label="Next"><span aria-hidden="true">»</span></a></li> {% endif %} </ul> </nav> </div>
更多详情：https://docs.djangoproject.com/en/1.9/topics/pagination/
三、在自己写的脚本里调用django models
#!/usr/bin/env python # -*- coding:utf-8 -*- import os os.environ[‘DJANGO_SETTINGS_MODULE‘] = ‘django_project.settings‘ import django django.setup() from app01 import models result = models.UserInfo.objects.get(id=1) print(result)
四、用户认证
from django.contrib.auth.models import User class UserProfile(models.Model): user = models.OneToOneField(User) name = models.CharField(max_length=32)
from django.contrib.auth import authenticate,login,logout from django.contrib.auth.decorators import login_required @login_required def acc_home(request): return render(request,"index.html") def acc_login(request): if request.method == "POST": username = request.POST.get("username") password = request.POST.get("password") user = authenticate(username=username,password=password) #验证 if user is not None: login(request,user) #登录 return redirect("/app01/acc_home/") else: return render(request,"login.html") def acc_logout(request): logout(request) #退出
在前端显示用户名或对应的名字
<div> {% if request.user.is_authenticated %} <!--如果已经登录--> <span>{{ request.user }}</span> <!--用户名--> <span>{{ request.user.userprofile.name }}</span> <!--用户名在UserProfile表对应的名字--> {% endif %} </div>
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原文地址：http://www.cnblogs.com/melonjiang/p/5565799.html
