分页器
批量插入数据
# models.py
class Books(models.Model):
name = models.CharField(max_length=32)
price = models.DecimalField(max_digits=5, decimal_places=2)
publish = models.CharField(max_length=32)
# views.py
def book_page(request):
# 第一种方案，每循环依次，操作一下数据库，性能低
# for i in range(1000):
# book = models.Books.objects.create(name='图书%s' % i, price=i + 10, publish='北京出版社')
# 分批插入
book_list = []
for i in range(1000):
book = models.Books(name='图书%s' % i, price=i + 10, publish='北京出版社')
book_list.append(book)
models.Books.objects.bulk_create(book_list, batch_size=10) # batch_size 分几批插入
return HttpResponse('ok')
# urls.py
url(r'^book_page/', views.book_page),
分页器的方法
def books_page(request):
from django.core.paginator import Paginator
book_list = models.Books.objects.all()
paginator = Paginator(book_list, 10)
# Paginator对象属性
print(paginator.count)
print(paginator.num_pages)
print(paginator.per_page)
print(paginator.page_range)
print(paginator.page(1))
# Page对象的属性和方法
page = paginator.page(2)
print(page.has_next())
print(page.next_page_number())
print(page.has_previous())
print(page.previous_page_number())
print(page.object_list)
print(page.number)
return render(request, 'book_page.html', locals())
'''
# Paginator对象属性
paginator.count # 数据总条数
paginator.num_pages # 总页数
paginator.per_page # 每页显示条数
paginator.page_range # range(1, 101)
paginator.page(1)
# Page对象的属性和方法
page = paginator.page(2)
page.has_next # 是否有下一页
page.next_page_number # 下一页页码
page.has_previous # 是否有上一页
page.previous_page_number # 上一页页码
page.object_list # 分页之后的数据列表
page.number # 当前页
'''
分页器使用
后端
from django.shortcuts import render, HttpResponse, redirect
from app01 import models
from django.core.paginator import Paginator
def book_page(request):
current_num = int(request.GET.get('page_num', 1))
book_list = models.Books.objects.all()
paginator = Paginator(book_list, 20)
# 如果页码不在范围内直接赋值为1，相当于调到第一页
try:
page = paginator.page(current_num)
except Exception as e:
current_num = 1
page = paginator.page(current_num)
# 将页码分为前五后五的情况，总数为11页
if paginator.num_pages > 11:
if current_num - 5 < 1:
page_range = range(1, 12)
elif current_num + 5 > paginator.num_pages:
page_range = range(paginator.num_pages - 10, paginator.num_pages + 1)
else:
page_range = range(current_num - 5, current_num + 6)
else:
page_range = paginator.page_range
return render(request, 'book_page.html', locals())
前端
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<title>Title</title>
<script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<link
href="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/3.4.1/css/bootstrap.min.css"
rel="stylesheet"
/>
<script src="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/3.4.1/js/bootstrap.min.js"></script>
</head>
<body>
<div class="row">
<div class="col-md-8 col-md-offset-2">
<table class="table table-striped table-hover">
<thead>
<tr>
<td>id</td>
<td>书名</td>
<td>价格</td>
<td>出版社</td>
</tr>
</thead>
<tbody>
{# 只显示当前页码的数据 #} {% for book in page.object_list %}
<tr>
<td>{{ book.id }}</td>
<td>{{ book.name }}</td>
<td>{{ book.price }}</td>
<td>{{ book.publish }}</td>
</tr>
{% endfor %}
</tbody>
</table>
</div>
<div class="col-md-6 col-md-offset-4">
<nav aria-label="Page navigation">
<ul class="pagination">
{# 判断当在第一页时，就没有上一页了，将上一页按钮设置为不可选中 #}
{% if page.has_previous %}
<li>
<a
href="/book_page/?page_num={{ page.previous_page_number }}"
aria-label="Previous"
>
<span aria-hidden="true">«</span>
</a>
</li>
{% else %}
<li class="disabled">
<a href="#" aria-label="Previous">
<span aria-hidden="true">«</span>
</a>
</li>
{% endif %} {#
使用GET方法提交当前页数给后端，后端处理后获取显示多少页码数进行循环
#} {% for foo in page_range %} {% if current_num == foo %}
<li class="active">
<a href="/book_page/?page_num={{ foo }}">{{ foo }}</a>
</li>
{% else %}
<li><a href="/book_page/?page_num={{ foo }}">{{ foo }}</a></li>
{% endif %} {% endfor %} {#
判断当在最后一页时，就没有最后一页了，将下一页按钮设置为不可选中 #}
{% if page.has_next %}
<li>
<a
href="/book_page/?page_num={{ page.next_page_number }}"
aria-label="Next"
>
<span aria-hidden="true">»</span>
</a>
</li>
{% else %}
<li class="disabled">
<a href="#" aria-label="Next">
<span aria-hidden="true">»</span>
</a>
</li>
{% endif %}
</ul>
</nav>
</div>
</div>
</body>
</html>
自定义分页器
当我们需要使用到非 django 内置的第三方功能或者组件代码的时候，我们一般情况下会创建一个名为 utils 的文件夹，在该文件夹内对模块进行功能性划分。eg：mypage.py
我们到了后期封装代码的时候，不再局限于函数，而是尽量朝面向对象去封装
将下面封装好的模板拷贝到 utils 文件夹下的 mypage.py（自定义的名字随意取）
class Pagination(object):
def __init__(self, current_page, all_count, per_page_num=2, pager_count=5):
"""
封装分页相关数据
:param current_page: 当前页
:param all_count: 数据库中的数据总条数
:param per_page_num: 每页显示的数据条数
:param pager_count: 最多显示的页码个数
"""
try:
current_page = int(current_page)
except Exception as e:
current_page = 1
if current_page < 1:
current_page = 1
self.current_page = current_page
self.all_count = all_count
self.per_page_num = per_page_num
# 总页码
all_pager, tmp = divmod(all_count, per_page_num)
if tmp:
all_pager += 1
self.all_pager = all_pager
self.pager_count = pager_count
self.pager_count_half = int((pager_count - 1) / 2)
@property
def start(self):
return (self.current_page - 1) * self.per_page_num
@property
def end(self):
return self.current_page * self.per_page_num
def page_html(self):
# 如果总页码 < 11个：
if self.all_pager <= self.pager_count:
pager_start = 1
pager_end = self.all_pager + 1
# 总页码 > 11
else:
# 当前页如果<=页面上最多显示11/2个页码
if self.current_page <= self.pager_count_half:
pager_start = 1
pager_end = self.pager_count + 1
# 当前页大于5
else:
# 页码翻到最后
if (self.current_page + self.pager_count_half) > self.all_pager:
pager_end = self.all_pager + 1
pager_start = self.all_pager - self.pager_count + 1
else:
pager_start = self.current_page - self.pager_count_half
pager_end = self.current_page + self.pager_count_half + 1
page_html_list = []
# 添加前面的nav和ul标签
page_html_list.append('''
<nav aria-label='Page navigation>'
<ul class='pagination'>
''')
first_page = '<li><a href="?page=%s">首页</a></li>' % (1)
page_html_list.append(first_page)
if self.current_page <= 1:
prev_page = '<li class="disabled"><a href="#">上一页</a></li>'
else:
prev_page = '<li><a href="?page=%s">上一页</a></li>' % (self.current_page - 1,)
page_html_list.append(prev_page)
for i in range(pager_start, pager_end):
if i == self.current_page:
temp = '<li class="active"><a href="?page=%s">%s</a></li>' % (i, i,)
else:
temp = '<li><a href="?page=%s">%s</a></li>' % (i, i,)
page_html_list.append(temp)
if self.current_page >= self.all_pager:
next_page = '<li class="disabled"><a href="#">下一页</a></li>'
else:
next_page = '<li><a href="?page=%s">下一页</a></li>' % (self.current_page + 1,)
page_html_list.append(next_page)
last_page = '<li><a href="?page=%s">尾页</a></li>' % (self.all_pager,)
page_html_list.append(last_page)
# 尾部添加标签
page_html_list.append('''
</nav>
</ul>
''')
return ''.join(page_html_list)
后端模板
from utils.mypage import Pagination # 导入模板
# 书籍的展示
def books(request):
# 先查询出所有要展示的数据信息，
book_queryset = models.Book.objects.all()
current_page = request.GET.get('page',1)
all_count = book_queryset.count()
# 传值生成对象
page_obj = Pagination(current_page=current_page,all_count=all_count)
# 直接对总数据进行切片操作
page_queryset = book_queryset[page_obj.start:page_obj.end]
# 将page_queryset传递到页面，替换之前的book_queryset
return render(request,'books.html',locals())
前端
<div class="text-center">{{ page_obj.page_html|safe }}</div>
实例
{% extends 'home.html' %} {% block main %}
<script>
$(".index").removeClass("active");
$(".books").addClass("active");
$(".publish").removeClass("active");
$(".author").removeClass("active");
</script>
<div>
<div class="panel panel-primary">
<div class="panel-heading">
<h3 class="panel-title">图书管理</h3>
</div>
<div class="panel-body">
<div>
<a href="/book_add/" class="btn btn-success pull-right">添加书籍</a>
</div>
<br />
<br />
<table class="table table-striped table-hover table-bordered">
<thead>
<tr>
<th>ID</th>
<th>书名</th>
<th>价格</th>
<th>出版日期</th>
<th>出版社</th>
<th>作者</th>
<th>操作</th>
</tr>
</thead>
<tbody>
{% for book in page_queryset %}
<tr>
<td>{{ book.id }}</td>
<td class="warning">{{ book.title }}</td>
<td class="info">{{ book.price }}</td>
<td class="dark">{{ book.publish_date|date:'Y-m-d' }}</td>
<td class="success">{{ book.publish.name }}</td>
<td>
{% for author in book.authors.all %} {% if forloop.last %} {{
author.name }} {% else %} {{ author.name }}、 {% endif %} {%
endfor %}
</td>
<td>
<a
href="{% url 'book_edit' book.pk %}"
class="btn btn-primary btn-xs"
>编辑</a
>
<a
href="{% url 'book_delete' book.pk %}"
class="btn btn-danger btn-xs"
>删除</a
>
<button
type="button"
class="btn btn-primary btn-lg"
data-toggle="modal"
data-target="#myModal"
id="bbb"
onclick="AA('{{ html }}')"
>
Launch
</button>
</td>
</tr>
{% endfor %}
</tbody>
</table>
{# 只需要这一行代码就可以实现分页 #}
<div class="text-center">{{ page_obj.page_html|safe }}</div>
</div>
</div>
</div>
{% endblock %}