首页
所有分类
TAGS
文字工具 EMOJI BIBLE
编程 Python

django rest framework 数据的查找、过滤、排序的示例

Posted in Python onJune 25, 2018

对于管理系统，常常需要展示列表数据，我们对于列表内的数据常常需要查找、过滤、排序等操作，其中查找等操作大部分是在后台进行的。django rest framework可以轻松的实现数据的查找、过滤等操作。接下来我们将以实际的例子进行介绍。

示例代码github地址： https://github.com/jinjidejuren/drf_learn

例如cmdb系统，作为资产管理系统常常需要对数据进行过滤或查找，获取期望的信息。

实现model

1.在这个示例项目中，需要实现对物理服务器的条件过滤，物理服务器的model列表如下（apps/assets/models.py文件）:

class Server(models.Model):
  """
  物理服务器
  """
  status_choice = (
    ('online', '上线'),
    ('offline', '下线'),
    ('normal', '正常'),
    ('abnormal', '异常')
  )

  server_name = models.CharField(verbose_name=u'服务器名称', max_length=128, blank=False, null=False)
  server_num = models.CharField(verbose_name=u'服务器编号', max_length=128, blank=True, null=True)
  brand = models.CharField(verbose_name=u'品牌', max_length=64, blank=True, null=True)
  model = models.CharField(verbose_name=u'型号', max_length=64, blank=True, null=True)
  cpus = models.IntegerField(verbose_name=u'cpu核数', default=0)
  ram = models.IntegerField(verbose_name=u'内存大小', default=0)
  disk = models.IntegerField(verbose_name=u'磁盘大小', default=0)
  product_date = models.DateTimeField(verbose_name=u'生产日期', auto_now_add=True)
  status = models.CharField(verbose_name=u'状态', max_length=16, choices=status_choice)

  created_time = models.DateTimeField(verbose_name=u'创建时间', auto_now_add=True)
  modified_time = models.DateTimeField(verbose_name=u'修改时间', auto_now_add=True)

  class Meta:
    verbose_name = u'服务器'
    verbose_name_plural = verbose_name

  def __str__(self):
    return self.server_name

实现serializer

接下来需要实现server这个model的序列化类，在apps/assets/serializers.py中编写:

class ServiceSerializer(serializers.ModelSerializer):
  """
  服务器序列化
  """

  class Meta:
    model = Server
    fields = ('id', 'server_name', 'server_num', 'brand', 'model', 'cpus',
         'ram', 'disk', 'product_date', 'status', 'created_time',
         'modified_time')

对于fields来说，可以使用 _ all _ 来代表所有的字段，除了model中定义的field外，序列化还可以指定其他的信息，比如嵌套信息或者自定义的信息。具体可以取决于业务逻辑。

实现modelviewset

对于modelviewset，我们可以围绕它对用户请求做相应的处理。常见的是对model进行增加、删除、查找、修改等。在这部分我们需要实现ServerViewSet：

class ServerViewSet(viewsets.ModelViewSet):
  """
  物理服务器视图
  """
  queryset = Server.objects.all().order_by('-created_time')
  serializer_class = ServerSerializer
  pagination_class = MyFormatResultsSetPagination

queryset指定返回列表的形式，所有的信息都返回，并且按照创建时间逆序排列，这样可以把最新的信息先返回，比较符合用户的操作习惯。

serializer_class定义了返回的序列化格式为ServerSerializer所指定的fields内容

pagination_class 指定了分页的类型，这个MyFormatResultsSetPagination是我们的自定义类型

实现router

如果用户想要访问server的信息，需要指定server的路由，这个和之前介绍的类似。需要的嗯一个一个router对象，并且将server的路由注册进去。

from rest_framework import routers

router = routers.DefaultRouter()
router.register(r'servers', views.ServerViewSet, base_name='servers')

urlpatterns = [
  url(r'^', include(router.urls))
]

对于servers的访问都由ServerViewSet进行处理。

尝试访问

http://127.0.0.1:8060/assets/v1/servers/ ，信息如下：

django rest framework 数据的查找、过滤、排序的示例

注：我们需要添加示例信息，作为后续的各种测试使用。

按照条件获取

在日常操作中，我们需要获取指定条件的数据，例如对于物理服务器，我们需要指定品牌、指定cpu核数、指定内存大小等。有时候我们需要按照cpu核数进行排序。这些都需要我们对ServerViewSet进行更多的拓展。

如果进行条件过滤，需要首先安装django-filter模块：

pip install django-filter

在配置文件settings/base.py中添加应用django_filters：

INSTALLED_APPS = [
  # 'django.contrib.admin',
  'django.contrib.auth',
  'django.contrib.contenttypes',
  'django.contrib.sessions',
  'django.contrib.messages',
  'django.contrib.staticfiles',
  'rest_framework',
  'django_filters',
  'apps.assets',
  'apps.rbac'
]

在apps/assets/views.py顶部包含如下包：

from django_filters.rest_framework import DjangoFilterBackend
from rest_framework import filters
from django_filters import rest_framework

ServerViewSet可以添加相应的过滤条件：

class ServerViewSet(viewsets.ModelViewSet):
  """
  物理服务器视图
  """
  queryset = Server.objects.all()
  serializer_class = ServerSerializer
  pagination_class = MyFormatResultsSetPagination
  filter_backends = (rest_framework.DjangoFilterBackend, filters.SearchFilter, filters.OrderingFilter, )
  filter_class = ServerFilter
  search_fields = ('server_name', '=brand', 'status', )
  ordering_fields = ('cpus', 'ram', 'disk', 'product_date', )
  ordering = ('-created_time', )

这里的filter_backends指定了过滤的类型，此处设定了DjangoFilterBackend（过滤）、SearchFilter（搜索）和OrderingFIlter（排序）。

1.过滤

过滤设定了过滤的配置类为ServerFilter，关于ServerFilter在apps/assets/filters.py文件中进行了定义：

import django_filters

from .models import *


class ServerFilter(django_filters.rest_framework.FilterSet):
  """
  物理服务器过滤器
  """

  server_name = django_filters.CharFilter(name='server_name', lookup_expr='icontains')
  brand = django_filters.CharFilter(name='brand', lookup_expr='icontains')
  cpus = django_filters.NumberFilter(name='cpus')
  ram = django_filters.NumberFilter(name='ram')
  disk = django_filters.NumberFilter(name='disk')

  class Meta:
    model = Server
    fields = ['server_name', 'brand', 'cpus', 'ram', 'disk', ]

也就是说可以通过'server_name', ‘brand', ‘cpus', ‘ram', ‘disk'对物理服务器的信息进行过滤，得到相应的序列化列表。

例如获取cpu为24核的物理服务器：

django rest framework 数据的查找、过滤、排序的示例

得到物理服务器列表中cpu都为24:

GET /assets/v1/servers/?server_name=&brand=&cpus=24&ram=&disk=
HTTP 200 OK
Allow: GET, POST, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
  "results": [
    {
      "id": 9,
      "server_name": "data-server2",
      "server_num": "server-01-shanghai",
      "brand": "hp",
      "model": "HPE Apollo 4200 Gen9",
      "cpus": 24,
      "ram": 64,
      "disk": 2500,
      "product_date": "2018-06-23T13:51:09.641473Z",
      "status": "online",
      "created_time": "2018-06-23T13:51:09.642583Z",
      "modified_time": "2018-06-23T13:51:09.642764Z"
    },
    {
      "id": 8,
      "server_name": "data-server2",
      "server_num": "server-01-shanghai",
      "brand": "hp",
      "model": "HPE Apollo 4200 Gen9",
      "cpus": 24,
      "ram": 64,
      "disk": 5000,
      "product_date": "2018-06-23T13:51:02.466031Z",
      "status": "online",
      "created_time": "2018-06-23T13:51:02.467274Z",
      "modified_time": "2018-06-23T13:51:02.467471Z"
    },
    {
      "id": 7,
      "server_name": "data-server1",
      "server_num": "server-01-shanghai",
      "brand": "hp",
      "model": "HPE Apollo 4200 Gen9",
      "cpus": 24,
      "ram": 64,
      "disk": 5000,
      "product_date": "2018-06-23T13:50:55.622403Z",
      "status": "offline",
      "created_time": "2018-06-23T13:50:55.623315Z",
      "modified_time": "2018-06-23T13:50:55.623431Z"
    },
    {
      "id": 6,
      "server_name": "data-server",
      "server_num": "server-01-shanghai",
      "brand": "hp",
      "model": "HPE Apollo 4200 Gen9",
      "cpus": 24,
      "ram": 64,
      "disk": 5000,
      "product_date": "2018-06-23T13:50:48.088028Z",
      "status": "online",
      "created_time": "2018-06-23T13:50:48.089433Z",
      "modified_time": "2018-06-23T13:50:48.089703Z"
    },
    {
      "id": 5,
      "server_name": "harbor-server3",
      "server_num": "server-01-beijing",
      "brand": "dell",
      "model": "Rack",
      "cpus": 24,
      "ram": 128,
      "disk": 5000,
      "product_date": "2018-06-23T13:49:27.590015Z",
      "status": "offline",
      "created_time": "2018-06-23T13:49:27.590980Z",
      "modified_time": "2018-06-23T13:49:27.591097Z"
    },
    {
      "id": 4,
      "server_name": "harbor-server3",
      "server_num": "server-01-beijing",
      "brand": "dell",
      "model": "Rack",
      "cpus": 24,
      "ram": 128,
      "disk": 5000,
      "product_date": "2018-06-23T13:49:23.783337Z",
      "status": "abnormal",
      "created_time": "2018-06-23T13:49:23.784243Z",
      "modified_time": "2018-06-23T13:49:23.784500Z"
    },
    {
      "id": 3,
      "server_name": "harbor-server2",
      "server_num": "server-01-beijing",
      "brand": "dell",
      "model": "Rack",
      "cpus": 24,
      "ram": 128,
      "disk": 5000,
      "product_date": "2018-06-23T13:49:16.348672Z",
      "status": "online",
      "created_time": "2018-06-23T13:49:16.349555Z",
      "modified_time": "2018-06-23T13:49:16.349663Z"
    },
    {
      "id": 2,
      "server_name": "harbor-server1",
      "server_num": "server-02-beijing",
      "brand": "dell",
      "model": "Rack",
      "cpus": 24,
      "ram": 128,
      "disk": 5000,
      "product_date": "2018-06-23T13:48:57.853354Z",
      "status": "online",
      "created_time": "2018-06-23T13:48:57.853990Z",
      "modified_time": "2018-06-23T13:48:57.854098Z"
    },
    {
      "id": 1,
      "server_name": "harbor-server",
      "server_num": "server-01-beijing",
      "brand": "dell",
      "model": "Rack",
      "cpus": 24,
      "ram": 128,
      "disk": 5000,
      "product_date": "2018-06-23T13:48:48.777153Z",
      "status": "online",
      "created_time": "2018-06-23T13:48:48.778048Z",
      "modified_time": "2018-06-23T13:48:48.778166Z"
    }
  ],
  "pagination": 9,
  "page_size": 10,
  "page": 1
}

2.搜索

搜索需要指定 search 关键字需要查询的信息，例如搜索名称为‘test'开头的服务器：

http://127.0.0.1:8060/assets/v1/servers/?search=test

获取列表：

HTTP 200 OK
Allow: GET, POST, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
  "results": [
    {
      "id": 14,
      "server_name": "test-server1",
      "server_num": "server-01-shanghai",
      "brand": "dell",
      "model": "Modular",
      "cpus": 32,
      "ram": 256,
      "disk": 500,
      "product_date": "2018-06-23T13:52:40.583743Z",
      "status": "offline",
      "created_time": "2018-06-23T13:52:40.584409Z",
      "modified_time": "2018-06-23T13:52:40.584512Z"
    },
    {
      "id": 13,
      "server_name": "test-server",
      "server_num": "server-01-shanghai",
      "brand": "dell",
      "model": "Modular",
      "cpus": 32,
      "ram": 256,
      "disk": 2500,
      "product_date": "2018-06-23T13:52:24.760819Z",
      "status": "normal",
      "created_time": "2018-06-23T13:52:24.761475Z",
      "modified_time": "2018-06-23T13:52:24.761578Z"
    }
  ],
  "pagination": 2,
  "page_size": 10,
  "page": 1
}

在search_fields中可以指定多种查找方式：

‘^name' 以name开头

‘=name' 精确匹配

‘@' 全局检索（只有mysql数据源支持）

‘$' 正则匹配

对应的search_fileds示例如下：

search_fields = ('^server_name', '=brand', 'status', )

3.排序

在ordering字段指定了默认排序方式（按照创建时间逆序排序）：

ordering = ('-created_time', )

也可以使用如下方式指定：

queryset = Server.objects.all().order_by('-created_time')

如果要自定义排序字段，需要指定 ordering 字段的内容：

例如按照内存大小排列服务器：

http://127.0.0.1:8060/assets/v1/servers/?ordering=ram

获取的信息列表如下：

HTTP 200 OK
Allow: GET, POST, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
  "results": [
    {
      "id": 6,
      "server_name": "data-server",
      "server_num": "server-01-shanghai",
      "brand": "hp",
      "model": "HPE Apollo 4200 Gen9",
      "cpus": 24,
      "ram": 64,
      "disk": 5000,
      "product_date": "2018-06-23T13:50:48.088028Z",
      "status": "online",
      "created_time": "2018-06-23T13:50:48.089433Z",
      "modified_time": "2018-06-23T13:50:48.089703Z"
    },
    {
      "id": 7,
      "server_name": "data-server1",
      "server_num": "server-01-shanghai",
      "brand": "hp",
      "model": "HPE Apollo 4200 Gen9",
      "cpus": 24,
      "ram": 64,
      "disk": 5000,
      "product_date": "2018-06-23T13:50:55.622403Z",
      "status": "offline",
      "created_time": "2018-06-23T13:50:55.623315Z",
      "modified_time": "2018-06-23T13:50:55.623431Z"
    },
    {
      "id": 8,
      "server_name": "data-server2",
      "server_num": "server-01-shanghai",
      "brand": "hp",
      "model": "HPE Apollo 4200 Gen9",
      "cpus": 24,
      "ram": 64,
      "disk": 5000,
      "product_date": "2018-06-23T13:51:02.466031Z",
      "status": "online",
      "created_time": "2018-06-23T13:51:02.467274Z",
      "modified_time": "2018-06-23T13:51:02.467471Z"
    },
    {
      "id": 9,
      "server_name": "data-server2",
      "server_num": "server-01-shanghai",
      "brand": "hp",
      "model": "HPE Apollo 4200 Gen9",
      "cpus": 24,
      "ram": 64,
      "disk": 2500,
      "product_date": "2018-06-23T13:51:09.641473Z",
      "status": "online",
      "created_time": "2018-06-23T13:51:09.642583Z",
      "modified_time": "2018-06-23T13:51:09.642764Z"
    },
    {
      "id": 1,
      "server_name": "harbor-server",
      "server_num": "server-01-beijing",
      "brand": "dell",
      "model": "Rack",
      "cpus": 24,
      "ram": 128,
      "disk": 5000,
      "product_date": "2018-06-23T13:48:48.777153Z",
      "status": "online",
      "created_time": "2018-06-23T13:48:48.778048Z",
      "modified_time": "2018-06-23T13:48:48.778166Z"
    },
    {
      "id": 2,
      "server_name": "harbor-server1",
      "server_num": "server-02-beijing",
      "brand": "dell",
      "model": "Rack",
      "cpus": 24,
      "ram": 128,
      "disk": 5000,
      "product_date": "2018-06-23T13:48:57.853354Z",
      "status": "online",
      "created_time": "2018-06-23T13:48:57.853990Z",
      "modified_time": "2018-06-23T13:48:57.854098Z"
    },
    {
      "id": 3,
      "server_name": "harbor-server2",
      "server_num": "server-01-beijing",
      "brand": "dell",
      "model": "Rack",
      "cpus": 24,
      "ram": 128,
      "disk": 5000,
      "product_date": "2018-06-23T13:49:16.348672Z",
      "status": "online",
      "created_time": "2018-06-23T13:49:16.349555Z",
      "modified_time": "2018-06-23T13:49:16.349663Z"
    },
    {
      "id": 4,
      "server_name": "harbor-server3",
      "server_num": "server-01-beijing",
      "brand": "dell",
      "model": "Rack",
      "cpus": 24,
      "ram": 128,
      "disk": 5000,
      "product_date": "2018-06-23T13:49:23.783337Z",
      "status": "abnormal",
      "created_time": "2018-06-23T13:49:23.784243Z",
      "modified_time": "2018-06-23T13:49:23.784500Z"
    },
    {
      "id": 5,
      "server_name": "harbor-server3",
      "server_num": "server-01-beijing",
      "brand": "dell",
      "model": "Rack",
      "cpus": 24,
      "ram": 128,
      "disk": 5000,
      "product_date": "2018-06-23T13:49:27.590015Z",
      "status": "offline",
      "created_time": "2018-06-23T13:49:27.590980Z",
      "modified_time": "2018-06-23T13:49:27.591097Z"
    },
    {
      "id": 10,
      "server_name": "data-server2",
      "server_num": "server-01-shanghai",
      "brand": "hp",
      "model": "HPE Apollo 4200 Gen9",
      "cpus": 32,
      "ram": 256,
      "disk": 2500,
      "product_date": "2018-06-23T13:51:30.706187Z",
      "status": "online",
      "created_time": "2018-06-23T13:51:30.707754Z",
      "modified_time": "2018-06-23T13:51:30.707878Z"
    }
  ],
  "pagination": 14,
  "page_size": 10,
  "page": 1
}

上述的排序、过滤等操作可以组合使用，一般为前端的列表搜索查询提供接口支持。

小结

本章小结的内容介绍了django rest framework如何进行model的定义、序列化、增删改查以及搜索、排序等功能，是书写后端接口必须掌握的技巧。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持三水点靠木。

django rest framework 数据的查找、过滤、排序的示例

- Author -

linux_player_c（系统&开发）

声明：登载此文出于传递更多信息之目的，并不意味着赞同其观点或证实其描述。

Python 相关文章推荐
Python实现简单多线程任务队列
Feb 27 Python
python 写入csv乱码问题解决方法
Oct 23 Python
Python编程求解二叉树中和为某一值的路径代码示例
Jan 04 Python
python使用pycharm环境调用opencv库
Feb 11 Python
对python的文件内注释 help注释方法
May 23 Python
Python3实现的回文数判断及罗马数字转整数算法示例
Mar 27 Python
Django模型修改及数据迁移实现解析
Aug 01 Python
python tkinter控件布局项目实例
Nov 04 Python
python递归函数求n的阶乘,优缺点及递归次数设置方式
Apr 02 Python
Django-migrate报错问题解决方案
Apr 21 Python
Python定时任务APScheduler安装及使用解析
Aug 07 Python
python一些性能分析的技巧
Aug 30 Python
python使用turtle库绘制树
Jun 25 #Python
使用Python微信库itchat获得好友和群组已撤回的消息
Jun 24 #Python
python库lxml在linux和WIN系统下的安装
Jun 24 #Python
Python3中详解fabfile的编写
Jun 24 #Python
关于python写入文件自动换行的问题
Jun 23 #Python
利用Python读取txt文档的方法讲解
Jun 23 #Python
python读取一个目录下所有txt里面的内容方法
Jun 23 #Python
创业计划书(312) 心得体会(660) 职业生涯规划书(234) 岗位职责(1324) 自荐信(981) 求职信(1029) 自我评价(886) 推荐信(292) 演讲稿(869) 思想汇报(404)
You might like
在WINDOWS中设置计划任务执行PHP文件的方法
2011/12/19 PHP
PHP开发框架kohana中处理ajax请求的例子
2014/07/14 PHP
HTML中嵌入PHP的简单方法
2016/02/16 PHP
javascript函数中的arguments参数
2010/08/01 Javascript
JavaScript初学者需要了解10个小技巧
2010/08/25 Javascript
使用隐藏的new来创建对象
2011/03/29 Javascript
jquery调整表格行tr上下顺序实例讲解
2016/01/09 Javascript
学习AngularJs:Directive指令用法（完整版）
2016/04/26 Javascript
JavaScript基本类型值-Undefined、Null、Boolean
2017/02/23 Javascript
Vue.js结合bootstrap实现分页控件
2017/03/10 Javascript
vue.js watch经常失效的场景与解决方案
2021/01/07 Vue.js
[04:53]DOTA2英雄基础教程 祈求者
2014/01/03 DOTA
Python 深入理解yield
2008/09/06 Python
零基础写python爬虫之神器正则表达式
2014/11/06 Python
python3抓取中文网页的方法
2015/07/28 Python
详解Python中open()函数指定文件打开方式的用法
2016/06/04 Python
python中is与双等于号“==”的区别示例详解
2017/11/21 Python
Python socket模块实现的udp通信功能示例
2019/04/10 Python
十个Python练手的实战项目，学会这些Python就基本没问题了(推荐)
2019/04/26 Python
python快速编写单行注释多行注释的方法
2019/07/31 Python
Python爬虫自动化爬取b站实时弹幕实例方法
2021/01/26 Python
世界首屈一指的钓鱼用品商店：TackleDirect
2016/07/26 全球购物
法国一家芭蕾舞鞋公司：Repetto
2018/11/12 全球购物
DOUGLAS波兰：在线销售香水和化妆品
2020/07/05 全球购物
草莓网中国：StrawberryNet中国
2020/08/17 全球购物
应届毕业生个人自荐信范文
2013/11/30 职场文书
毕业自荐书
2013/12/09 职场文书
国贸专业求职信
2014/06/28 职场文书
信用卡逾期证明示例
2014/09/13 职场文书
群众路线教育实践活动整改落实情况汇报
2014/10/28 职场文书
毕业论文指导教师评语
2014/12/30 职场文书
中学生思想品德评语
2014/12/31 职场文书
小学生读书笔记范文
2015/06/30 职场文书
Python一些基本的图像操作和处理总结
2021/06/23 Python
Win11更新失败并提示0xc1900101
2022/04/19 数码科技
关于pytest结合csv模块实现csv格式的数据驱动问题
2022/05/30 Python