Django内置的序列化与分页器

"""
如果发现你可以直接使用MySQL但是无法使用sqlite3
不要慌张不要恐惧 你只需要按照之前MySQL的操作将sqlite3的驱动装一下即可
"""
# 需求:在前端给我获取到后端用户表里面所有的数据 并且要是列表套字典
import json
from django.http import JsonResponse
from django.core import serializers
def ab_ser(request):
    user_queryset = models.User.objects.all()
    # [{},{},{},{},{}]
    # user_list = []
    # for user_obj in user_queryset:
    #     tmp = {
    #         'pk':user_obj.pk,
    #         'username':user_obj.username,
    #         'age':user_obj.age,
    #         'gender':user_obj.get_gender_display()
    #     }
    #     user_list.append(tmp)
    # return JsonResponse(user_list,safe=False)  除了字典,序列化其他要加safe=False
    # return render(request,'ab_ser.html',locals())

    # 序列化
    res = serializers.serialize('json',user_queryset)
    """会自动帮你将数据变成json格式的字符串 并且内部非常的全面"""
    return HttpResponse(res)
"""
[
 {"pk": 1, "username": "jason", "age": 25, "gender": "male"}, 
 {"pk": 2, "username": "egon", "age": 31, "gender": "female"},
 {"pk": 3, "username": "kevin", "age": 32, "gender": "others"}, 
 {"pk": 4, "username": "tank", "age": 40, "gender": 4}
 ]
前后端分离的项目
    作为后端开发的你只需要写代码将数据处理好
    能够序列化返回给前端即可 
        再写一个接口文档 告诉前端每个字段代表的意思即可
        
        
[
{   "model": "app01.user", 
    "pk": 1, 
    "fields": {"username": "jason", "age": 25, "gender": 1}}, 
    
{   "model": "app01.user", 
    "pk": 2, 
    "fields": {"username": "egon", "age": 31, "gender": 2}}, 
    
{   "model": "app01.user", 
    "pk": 3, 
    "fields": {"username": "kevin", "age": 32, "gender": 3}},
     
{   "model": "app01.user", 
    "pk": 4, 
    "fields": {"username": "tank", "age": 40, "gender": 4}}
]
写接口就是利用序列化组件渲染数据然后写一个接口文档 该交代交代一下就完事
"""

内置view部分

from django.shortcuts import render
from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger

L = []
for i in range(999):
    L.append(i)

def index(request):
    current_page = request.GET.get('p')

    paginator = Paginator(L, 10)
    # per_page: 每页显示条目数量
    # count:    数据总个数
    # num_pages:总页数
    # page_range:总页数的索引范围，如: (1,10),(1,200)
    # page:     page对象
    try:
        posts = paginator.page(current_page)
        # has_next              是否有下一页
        # next_page_number      下一页页码
        # has_previous          是否有上一页
        # previous_page_number  上一页页码
        # object_list           分页之后的数据列表
        # number                当前页
        # paginator             paginator对象
    except PageNotAnInteger:
        posts = paginator.page(1)
    except EmptyPage:
        posts = paginator.page(paginator.num_pages)
    return render(request, 'index.html', {'posts': posts})

 内置分页html部分

    
    



    {% for item in posts %}
        
{{ item }}
    {% endfor %}



      
        {% if posts.has_previous %}
            { posts.previous_page_number }}">Previous
        {% endif %}
          
            Page {{ posts.number }} of {{ posts.paginator.num_pages }}.
          
          {% if posts.has_next %}
              { posts.next_page_number }}">Next
          {% endif %}