day 56 批量插入与分页器

 

ajax与sweetalret的使用

前端：

"en">

    "UTF-8">
    
    
    {% load static %}
    "stylesheet" href="{% static 'bootstrap-3.3.7-dist/css/bootstrap.min.css' %}">
    "stylesheet" href="{% static 'dist/sweetalert.css' %}">
    
    
    


class="container-fluid">
    
class="row">
        
class="col-md-6 col-md-offset-2">
            
class="text-center">数据展示
            

            class="table table-hover table-bordered table-striped">
                
                {% for user_obj in user_queryset %}
                    
                {% endfor %}
                

                

                    
序号
                    
用户名
                    
年龄
                    
性别
                    
class="text-center">操作
                
                
                

                        
{{ forloop.counter }}
                        
{{ user_obj.username }}
                        
{{ user_obj.age }}
                        
{{ user_obj.get_gender_display }}
                        
class="text-center">
                            "#" class="btn btn-primary btn-sm">编辑
                            "#" class="btn btn-danger btn-sm cancel" userId={{ user_obj.pk }}>删除
                        
                    
            
        
    

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

　　​

{{book}}

{% 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('''
                    

                ''')
        first_page = '
首页' % (1)
        page_html_list.append(first_page)

        if self.current_page <= 1:
            prev_page = '
上一页'
        else:
            prev_page = '
上一页' % (self.current_page - 1,)

        page_html_list.append(prev_page)

        for i in range(pager_start, pager_end):
            if i == self.current_page:
                temp = '
%s' % (i, i,)
            else:
                temp = '
%s' % (i, i,)
            page_html_list.append(temp)

        if self.current_page >= self.all_pager:
            next_page = '
下一页'
        else:
            next_page = '
下一页' % (self.current_page + 1,)
        page_html_list.append(next_page)

        last_page = '
尾页' % (self.all_pager,)
        page_html_list.append(last_page)
        # 尾部添加标签
        page_html_list.append('''
                                           
                                           
                                       ''')
        return ''.join(page_html_list)