day 56 批量插入与分页器

 

ajax与sweetalret的使用

前端:

<!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>
    {% load static %}
    <link rel="stylesheet" href="{% static 'bootstrap-3.3.7-dist/css/bootstrap.min.css' %}">
    <link rel="stylesheet" href="{% static 'dist/sweetalert.css' %}">
    <script src="{% static 'bootstrap-3.3.7-dist/css/bootstrap.min.css' %}"></script>
    <script src="{% static 'dist/sweetalert.min.js' %}"></script>
    <style>
        div.sweet-alert h2 {
            padding: 10px
        }
    </style>
</head>
<body>
<div class="container-fluid">
    <div class="row">
        <div class="col-md-6 col-md-offset-2">
            <h2 class="text-center">数据展示</h2>
            <br>
            <table class="table table-hover table-bordered table-striped">
                <thead>
                <tr>
                    <th>序号</th>
                    <th>用户名</th>
                    <th>年龄</th>
                    <th>性别</th>
                    <th class="text-center">操作</th>
                </tr>
                </thead>
                <tbody>
                {% for user_obj in user_queryset %}
                    <tr>
                        <td>{{ forloop.counter }}</td>
                        <td>{{ user_obj.username }}</td>
                        <td>{{ user_obj.age }}</td>
                        <td>{{ user_obj.get_gender_display }}</td>
                        <td class="text-center">
                            <a href="#" class="btn btn-primary btn-sm">编辑</a>
                            <a href="#" class="btn btn-danger btn-sm cancel" userId={{ user_obj.pk }}>删除</a>
                        </td>
                    </tr>
                {% endfor %}
                </tbody>
            </table>
        </div>
    </div>
</div>

<script>
    $('.cancel').click(function () {
        var $btn = $(this);
        swal({
                title: "Are you sure?",
                text: "You will not be able to recover this imaginary file!",
                type: "warning",
                showCancelButton: true,
                confirmButtonClass: "btn-danger",
                confirmButtonText: "Yes, delete it!",
                cancelButtonText: "No, cancel plx!",
                closeOnConfirm: false,
                closeOnCancel: false,
                showLoaderOnConfirm: true

            },
            function (isConfirm) {
                if (isConfirm) {
                    $.ajax({
                        url: '',
                        type: 'post',
                        data: {'delete_id': $btn.attr('userId')},
                        success: function (data) {
                            if (data.code == 1000) {
                                swal("删除成功", data.msg, "success");
                                $btn.parent().parent().remove()
                            } else {
                                swal("有Bug", "发生了未知的错误", "warning");
                            }
                        }
                    });
                } else {
                    swal("Cancelled", "Your imaginary file is safe :)", "error");
                }
            });
    })
</script>
</body>
</html>

后端:

from django.shortcuts import render
from app01 import models
from django.http import JsonResponse
import time

# Create your views here.
def home(request):
    if request.is_ajax():
        back_dic = {'code': 1000, 'msg': ''}
        delete_id = request.POST.get('delete_id')
        time.sleep(2)
        models.User.objects.filter(pk=delete_id).delete()
        back_dic['msg'] = '数据删除成功'
        return JsonResponse(back_dic)
    user_queryset = models.User.objects.all()
    return render(request, 'home.html', locals())

模型层:

from django.db import models


# Create your models here.

class User(models.Model):
    username = models.CharField(max_length=32)
    age = models.IntegerField()
    gender_choice = (
        (1, 'male'),
        (2, 'female'),
        (3, 'other'),
    )

    gender = models.IntegerField(choices=gender_choice)

 

bulk_create批量插入数据

​ for i in range (1000):

​   models.Book.objects.create(title='第%本书'%i)

  ​ (这条指令运行很慢,花了六百多毫秒)

 

​ book_list=[ ]

​ for i in rage(10000):

​   book_list.append(models.Book(title='第%本书'%i))

 

   批量插入数据 建议使用bulk_create方法

 

​   models.Book.objects.bulk_create(book_list)

​ """两者差距很大"""

 

分页器

后端

​ 自定义分页器的使用

book_queryset=models.book.objects.all()#你想要分页展示的数据

current_page=request.GET.get('page',1)#获取当前页

all_count=book_queryset.count()#看一共有多少条数据

page_queryset=book_queryset[page_obj.start:page_obj.end]

return render (request.'index.html',locals())

前端

​ {% for book in page_queryset %} 将页面上原本的queryset全部换成切片之后的queryset即可

  ​ <p>{{book}}</p>

{% endfor %}

{{page_obj.page_html|safe}}告诉这是安全的可以读取

 

分页器:

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

        用法:
        queryset = model.objects.all()
        page_obj = Pagination(current_page,all_count)
        page_data = queryset[page_obj.start:page_obj.end]
        获取数据用page_data而不再使用原始的queryset
        获取前端分页样式用page_obj.page_html
        """
        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)
上一篇:支持向量机,从入门到精通


下一篇:day 56小结