2.批量插入数据与自定义分页器

批量插入数据

# 先创建一个Book表
class Book(models.Model):
    title = models.CharField(max_length=32)
    
    
# ab_pl.html    
{% for book_obj in book_queryset %}
    <p>{{ book_obj.title }}</p>
{% endfor %}
    
    
# views.py
def ab_pl(request):
    # 先给Book插入五百条数据
    # for i in range(500):
        models.Book.objects.create(title='第%s本书'%i)
    # 再将所有的数据查询并展示到前端页面
    # book_queryset = models.Book.objects.all()
    # return render(request,'ab_pl.html',locals())
    
    # 批量插入数据
    book_list = []
    for i in range(500):
        book_obj = models.Book(title='第%s本书'%i)
        book_list.append(book_obj)
    models.Book.objects.bulk_create(book_list)
    book_queryset = models.Book.objects.all()
    return render(request,'ab_pl.html',locals())

# 当你想要批量插入数据的时候 使用orm给你提供的bulk_create能够大大的减少操作时间

 

自定义分页器

ab_pl.html

<nav aria-label="Page navigation">
  <ul class="pagination">
    <li>
      <a href="#" aria-label="Previous">
        <span aria-hidden="true">&laquo;</span>
      </a>
    </li>
      {{ page_html|safe }}
    <li>
      <a href="#" aria-label="Next">
        <span aria-hidden="true">&raquo;</span>
      </a>
    </li>
  </ul>
</nav>

 

views.py

def ab_pl(request):    
    # 分页
    book_list = models.Book.objects.all()
    # 想访问哪一页
    current_page = request.GET.get('page',1)  # 如果获取不到当前页码，就展示第一页
    # 数据类型转换
    try:
        current_page = int(current_page)
    except Exception:
        current_page = 1

    # 每条展示多少条
    per_page_num = 10
    # 起始位置
    start_page = (current_page-1)*per_page_num
    # 终止位置
    end_page = current_page * per_page_num
    # 计算出需要多少页
    all_count = book_list.count()
    page_count, more = divmod(all_count,per_page_num)
    if more:
        page_count += 1

    page_html = ''
    xxx = current_page
    if current_page < 6:
        current_page = 6
    for i in range(current_page-5,current_page+6):
        if current_page == i:
            page_html += '<li class="active"><a href="?page=%s">%s</a></li>'%(i,i)
        else:
            page_html += '<li><a href="?page=%s">%s</a></li>'%(i,i)


    book_queryset = book_list[start_page:end_page]
    return render(request,'ab_pl.html',locals())