Django自定义分页
分页，就是分批次去数据库拿去数据并展示在前端。
ORM中的简单的分页，在ORM操作中就可以定义：
models.UserInfo.object.all()[0:10]
models.UserInfo.object.all()[10:20]
models.UserInfo.object.all()[20:30]
#每次取10条数据
在Django自带的分页做法流程：
url.py中做index.html 页面，views.index 。
在views中，写index函数。用paginator模块来实现分页。
#导入模块paginator
from django.core.paginator import Paginator,Page,PageNotAnInteger,EmptyPage
def index(request): """ 分页 """
current_page = request.GET.get("page") #current_page表示取第几页，
current_page = int(current_page) user_list = models.UserInfo.objects.all()
paginator = Paginator(user_list,10)
#用paginator分页,两个参数，分别是要被分页的表的别名，和每页的显示数据。
#per_page：每页显示的条目数量
#count：数据总个数
#num_pages：总页数
#page_range：总页数的索引范围 如：(1：10)，（100，200）
#page：page对象
#page的用法：
#posts = paginator.page(1) #括号里加数字，显示第几页
try:
postss = paginator.page(current_page) #postss可以点出下列的内容
except PageNotAnInteger as e:
postss = paginator.page(1)
except EmptyPage as e:
postss = paginator.page(1)
#has_next：是否有下一页
#next_page_number:下一页页码
#has_previous：是否有上一页
#previous_page_number:上一页页码
#object_list:分页之后的数据列表
#number：当前页
#paginator：paginator对象
return render(request,"index.html",{"postss":postss})
精简后的index：
from django.core.paginator import Paginator,Page,PageNotAnInteger,EmptyPage
def index(request): current_page = request.GET.get("page") user_list = models.UserInfo.objects.all() paginator = Paginator(user_list,10) try: posts = paginator.page(current_page) except PageNotAnInteger as e: posts = paginator.page(1) except EmptyPage as e: posts = paginator.page(1) return render(request,"index.html",{"posts":posts})
在template中写index.html页面
<html lang="en"> <head> <meta charset="utf-8"> <title></title> </head> <body> <h1>用户列表</h1> <u1> {% for item in postss.object_list % } <li>{{ item.name }}</li> {% endfor %} </u1>
<div>
{% if postss.has_previous %}
<a href="/index.html?page={{ postss.previous_page_number }}">上一页</a>
{% endif %}
{% for num in postss.paginator.page_range %}
<a href="/index.html?page={{num}}">{{num}}</a>
{% endfor %}
{% if postss.has_next %}
<a href="/index.html?page={{ postss.next_page_number }}">下一页</a>
{% endif %}
</div>
</body>
</html>
django自带的分页有不好的地方，就是他不能将页数部分显示，部分隐藏。它只能全部都显示出来，如果数据量大，页数多，那么在前端的展示就会不友好。所以要二次开发。
-------自行开发的分页--------
#要导入bootstrap class PageInfo(object): def __init__(self,current_page,all_count,per_page,base_url,show_page=11): """ :param current_page: :param all_count: 数据库总行数 :param per_page: 每页显示个数 :return: """ try: # 异常处理，页码出现非数字的，返回第一页 self.current_page = int(current_page) except Exception as e: # 返回第一页 self.current_page = 1 # 每页显示的个数 self.per_page = per_page #计算需要的页数，总数据行和每页显示的个数做比例 a,b = divmod(all_count,per_page) if b: a = a +1 self.all_pager = a self.show_page = show_page self.base_url = base_url def start(self): #每页的起始的数据行 return (self.current_page-1) * self.per_page def end(self): #每页的结束数据行 return self.current_page * self.per_page def pager(self): # v = "<a href='/custom.html?page=1'>1</a><a href='/custom.html?page=2'>2</a>" # return v page_list = [] #在页码中取一半 half = int((self.show_page-1)/2) # 如果数据总页数 < 11 if self.all_pager < self.show_page: begin = 1 stop = self.all_pager + 1 # 如果数据总页数 > 11 else: # 如果当前页 <=5,永远显示1,11 if self.current_page <= half: begin = 1 stop = self.show_page + 1 else: if self.current_page + half > self.all_pager: begin = self.all_pager - self.show_page + 1 stop = self.all_pager + 1 else: begin = self.current_page - half stop = self.current_page + half + 1 if self.current_page <= 1: prev = "<li><a href='#'>上一页</a></li>" else: prev = "<li><a href='%s?page=%s'>上一页</a></li>" %(self.base_url,self.current_page-1,) page_list.append(prev) for i in range(begin,stop): if i == self.current_page: #class标签是将当前页加标志色 temp = "<li class='active'><a href='%s?page=%s'>%s</a></li>" %(self.base_url,i,i,) else: temp = "<li><a href='%s?page=%s'>%s</a></li>" %(self.base_url,i,i,) page_list.append(temp) if self.current_page >= self.all_pager: nex = "<li><a href='#'>下一页</a></li>" else: nex = "<li><a href='%s?page=%s'>下一页</a></li>" %(self.base_url,self.current_page+1,) page_list.append(nex) return ''.join(page_list)
custom页面：
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title></title> <link rel="stylesheet" href="/static/plugins/bootstrap-3.3.7-dist/css/bootstrap.css" /> </head> <body> <h1>用户列表</h1> <ul> {% for row in user_list %} <li>{{ row.name }}</li> {% endfor %} </ul> <nav aria-label="Page navigation"> <ul class="pagination"> {{ page_info.pager|safe }} </ul> </nav> </body> </html>
views：
from utils.pager import PageInfo def custom(request): # 表示用户当前想要访问的页码: 8 all_count = models.UserInfo.objects.all().count() page_info = PageInfo(request.GET.get('page'),all_count,10,'/custom.html',11) user_list = models.UserInfo.objects.all()[page_info.start():page_info.end()] return render(request,'custom.html',{'user_list':user_list,'page_info':page_info})
全部views：
1 from django.shortcuts import render,HttpResponse 2 from app01 import models 3 from django.core.paginator import Paginator,Page,PageNotAnInteger,EmptyPage 4 def test(request): 5 # 创建数据 6 # models.UserType.objects.create(title='普通用户') 7 # models.UserType.objects.create(title='二逼用户') 8 # models.UserType.objects.create(title='牛逼用户') 9 10 # models.UserInfo.objects.create(name='方少伟',age=18,ut_id=1) 11 # models.UserInfo.objects.create(name='由秦兵',age=18,ut_id=2) 12 # models.UserInfo.objects.create(name='刘庚',age=18,ut_id=2) 13 # models.UserInfo.objects.create(name='陈涛',age=18,ut_id=3) 14 # models.UserInfo.objects.create(name='王者',age=18,ut_id=3) 15 # models.UserInfo.objects.create(name='杨涵',age=18,ut_id=1) 16 17 # 获取 18 # QuerySet[obj,obj,obj] 19 # result = models.UserInfo.objects.all() 20 # for obj in result: 21 # print(obj.name,obj.age,obj.ut_id,obj.ut.title) 22 23 # UserInfo，ut是FK字段 - 正向操作 PS: 一个用户只有一个用户类型 24 # obj = models.UserInfo.objects.all().first() 25 # print(obj.name,obj.age,obj.ut.title) 26 27 # UserType, 表名小写_set.all() - 反向操作 PS: 一个用户类型下可以有很多用户 28 # obj = models.UserType.objects.all().first() 29 # print('用户类型',obj.id,obj.title) 30 # for row in obj.userinfo_set.all(): 31 # print(row.name,row.age) 32 33 # result = models.UserType.objects.all() 34 # for item in result: 35 # print(item.title,item.userinfo_set.filter(name='xx')) 36 37 # obj 38 # [obj,obj,] 39 40 # result = models.UserInfo.objects.all().values('id','name') 41 # QuerySet[{'id':'xx','name':'xx'} ] 42 # for row in result: 43 # print(row) 44 45 # result = models.UserInfo.objects.all().values_list('id','name') 46 # QuerySet[(1,'f'), ] 47 # for row in result: 48 # print(row) 49 50 # 数据获取多个数据时 51 # 1. [obj,obj,obj,] 52 # models.UserInfo.objects.all() 53 # models.UserInfo.objects.filter(id__gt=1) 54 # result = models.UserInfo.objects.all() 55 # for item in result: 56 # print(item.name,item.ut.title) 57 58 # 2. [{id:1,name:fd},{id:1,name:fd},{id:1,name:fd},] 59 # models.UserInfo.objects.all().values('id','name') 60 # models.UserInfo.objects.filter(id__gt=1).values('id','name') 61 # 无法跨表 62 # result = models.UserInfo.objects.all().values('id','name') 63 # for item in result: 64 # print(item['id'],item['name']) 65 # 夸表 __ 66 # result = models.UserInfo.objects.all().values('id','name',"ut__title") 67 # for item in result: 68 # print(item['id'],item['name'],item['ut__title']) 69 70 71 # 3. [(1,df),(2,'df')] 72 # models.UserInfo.objects.all().values_list('id','name') 73 # models.UserInfo.objects.filter(id__gt=1).values_list('id','name') 74 # 无法跨表 75 # result = models.UserInfo.objects.all().values_list('id','name') 76 # for item in result: 77 # print(item[0],item[1]) 78 # 夸表 __ 79 # result = models.UserInfo.objects.all().values_list('id','name',"ut__title") 80 # for item in result: 81 # print(item[0],item[1],item[2]) 82 83 84 85 86 87 88 89 return HttpResponse('...') 90 91 from django.views import View 92 class Login(View): 93 """ 94 get 查 95 post 创建 96 put 更新 97 delete 删除 98 """ 99 def dispatch(self, request, *args, **kwargs): 100 print('before') 101 obj = super(Login,self).dispatch(request, *args, **kwargs) 102 print('after') 103 return obj 104 105 def get(self,request): 106 # return HttpResponse('Login.get') 107 return render(request,'login.html') 108 109 def post(self,request): 110 print(request.POST.get('user')) 111 return HttpResponse('Login.post') 112 113 114 115 116 def index(request): 117 """ 118 分页 119 :param request: 120 :return: 121 """ 122 # for i in range(300): 123 # name = "root" + str(i) 124 # models.UserInfo.objects.create(name=name,age=18,ut_id=1) 125 126 127 current_page = request.GET.get('page') 128 129 user_list = models.UserInfo.objects.all() 130 paginator = Paginator(user_list,10) 131 # per_page: 每页显示条目数量 132 # count: 数据总个数 133 # num_pages:总页数 134 # page_range:总页数的索引范围，如: (1,10),(1,200) 135 # page: page对象 136 try: 137 posts = paginator.page(current_page) 138 except PageNotAnInteger as e: 139 posts = paginator.page(1) 140 except EmptyPage as e: 141 posts = paginator.page(1) 142 # has_next 是否有下一页 143 # next_page_number 下一页页码 144 # has_previous 是否有上一页 145 # previous_page_number 上一页页码 146 # object_list 分页之后的数据列表 147 # number 当前页 148 # paginator paginator对象 149 return render(request,'index.html',{'posts':posts}) 150 151 from utils.pager import PageInfo 152 def custom(request): 153 # 表示用户当前想要访问的页码: 8 154 155 all_count = models.UserInfo.objects.all().count() 156 157 page_info = PageInfo(request.GET.get('page'),all_count,10,'/custom.html',11) 158 user_list = models.UserInfo.objects.all()[page_info.start():page_info.end()] 159 160 return render(request,'custom.html',{'user_list':user_list,'page_info':page_info})
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