批量插入数据&自定义分页器

1、批量插入数据

views.py

def booklist(request):
    # 批量插入10000条数据，且速度很快
    list = []
    for i in range(10000):
         list.append(models.Book(name='第%s本书' %i))
    
    # 插数据
    models.Book.objects.bulk_create(list)

    # 查询所有的书籍，展示到前端
    # book_list = models.Book.objects.all()

urls.py

from django.conf.urls import url
from django.contrib import admin
from app01 import views

urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^index/', views.index),
    url(r'^booklist/', views.booklist),
]

booklist.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://cdn.bootcss.com/jquery/3.4.1/jquery.min.js"></script>
    {#    <link rel="stylesheet" href="/static/bootstrap-3.3.7/css/bootstrap.min.css">#}
    {#    <script src="/static/bootstrap-3.3.7/js/bootstrap.min.js"></script>#}
    <link href="https://cdn.bootcss.com/twitter-bootstrap/3.4.1/css/bootstrap.min.css" rel="stylesheet">
    <script src="https://cdn.bootcss.com/twitter-bootstrap/3.4.1/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
    <div class="row">
        <div class="col-md-8 col-md-offset-2">
            <table class="table table-hover table-bordered table-striped">
                <thead>
                <tr>
                    <th>id</th>
                    <th>name</th>
                </tr>
                </thead>
                <tbody>
                {% for book in book_list %}
                    <tr>
                        <td>{{ book.pk }}</td>
                        <td>{{ book.name }}</td>
                    </tr>
                {% endfor %}
                </tbody>
            </table>
        </div>
    </div>
</div>
</body>
</html>

2、分页器

自己写太麻烦，已经有封装好的分页器，代码如下：

可以在app中新建一个utils目录，在utils中把以下代码写入一个py文件中；

class Pagination(object):
    def __init__(self, current_page, all_count, per_page_num=2, pager_count=11):
        """
        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)

后端调用：

views.py

from app01.utils import my_page
def booklist(request):
    book_list = models.Book.objects.all()

    # 当前页，默认是第一页
    current_page = request.GET.get("page", 1)
    # all_count:数据的总条数
    all_count = book_list.count()
    page_obj = my_page.Pagination(current_page=current_page, all_count=all_count, per_page_num=10)
    # page_obj.start代表起始位置；page_obj.end代表终止位置
    page_queryset = book_list[page_obj.start:page_obj.end]
    return render(request, 'booklist.html', locals())

前端调用：

booklist.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://cdn.bootcss.com/jquery/3.4.1/jquery.min.js"></script>
    <link href="https://cdn.bootcss.com/twitter-bootstrap/3.4.1/css/bootstrap.min.css" rel="stylesheet">
    <script src="https://cdn.bootcss.com/twitter-bootstrap/3.4.1/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
    <div class="row">
        <div class="col-md-8 col-md-offset-2">
            <table class="table table-hover table-bordered table-striped">
                <thead>
                <tr>
                    <th>id</th>
                    <th>name</th>
                </tr>
                </thead>
                <tbody>
                {% for book in page_queryset %}
                    <tr>
                        <td>{{ book.pk }}</td>
                        <td>{{ book.name }}</td>
                    </tr>
                {% endfor %}
                </tbody>
            </table>
        {{ page_obj.page_html|safe }}
        </div>
    </div>
</div>
</body>
</html>

效果如下：

知识点：

<li><a href="?page=1">1</a></li>   # 只写?page=1会自动补全当前路径

比如，完整路径是：http://127.0.0.1:8000/booklist/?page=1
它就会自动补全前面的http://127.0.0.1:8000/booklist/

批量插入数据&自定义分页器

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