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django rest framework中如何實(shí)現(xiàn)數(shù)據(jù)查找、過(guò)濾、排序操作

發(fā)布時(shí)間:2021-07-26 13:51:12 來(lái)源:億速云 閱讀:172 作者:小新 欄目:開(kāi)發(fā)技術(shù)

這篇文章主要介紹了django rest framework中如何實(shí)現(xiàn)數(shù)據(jù)查找、過(guò)濾、排序操作,具有一定借鑒價(jià)值,感興趣的朋友可以參考下,希望大家閱讀完這篇文章之后大有收獲,下面讓小編帶著大家一起了解一下。

對(duì)于管理系統(tǒng),常常需要展示列表數(shù)據(jù),我們對(duì)于列表內(nèi)的數(shù)據(jù)常常需要查找、過(guò)濾、排序等操作,其中查找等操作大部分是在后臺(tái)進(jìn)行的。django rest framework可以輕松的實(shí)現(xiàn)數(shù)據(jù)的查找、過(guò)濾等操作。

例如cmdb系統(tǒng),作為資產(chǎn)管理系統(tǒng)常常需要對(duì)數(shù)據(jù)進(jìn)行過(guò)濾或查找,獲取期望的信息。

實(shí)現(xiàn)model

1.在這個(gè)示例項(xiàng)目中,需要實(shí)現(xiàn)對(duì)物理服務(wù)器的條件過(guò)濾,物理服務(wù)器的model列表如下(apps/assets/models.py文件):

class Server(models.Model):
  """
  物理服務(wù)器
  """
  status_choice = (
    ('online', '上線'),
    ('offline', '下線'),
    ('normal', '正常'),
    ('abnormal', '異常')
  )

  server_name = models.CharField(verbose_name=u'服務(wù)器名稱(chēng)', max_length=128, blank=False, null=False)
  server_num = models.CharField(verbose_name=u'服務(wù)器編號(hào)', 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'型號(hào)', max_length=64, blank=True, null=True)
  cpus = models.IntegerField(verbose_name=u'cpu核數(shù)', default=0)
  ram = models.IntegerField(verbose_name=u'內(nèi)存大小', default=0)
  disk = models.IntegerField(verbose_name=u'磁盤(pán)大小', default=0)
  product_date = models.DateTimeField(verbose_name=u'生產(chǎn)日期', auto_now_add=True)
  status = models.CharField(verbose_name=u'狀態(tài)', max_length=16, choices=status_choice)

  created_time = models.DateTimeField(verbose_name=u'創(chuàng)建時(shí)間', auto_now_add=True)
  modified_time = models.DateTimeField(verbose_name=u'修改時(shí)間', auto_now_add=True)

  class Meta:
    verbose_name = u'服務(wù)器'
    verbose_name_plural = verbose_name

  def __str__(self):
    return self.server_name

實(shí)現(xiàn)serializer

接下來(lái)需要實(shí)現(xiàn)server這個(gè)model的序列化類(lèi),在apps/assets/serializers.py中編寫(xiě):

class ServiceSerializer(serializers.ModelSerializer):
  """
  服務(wù)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')

對(duì)于fields來(lái)說(shuō),可以使用 _ all _ 來(lái)代表所有的字段,除了model中定義的field外,序列化還可以指定其他的信息,比如嵌套信息或者自定義的信息。具體可以取決于業(yè)務(wù)邏輯。

實(shí)現(xiàn)modelviewset

對(duì)于modelviewset,我們可以圍繞它對(duì)用戶(hù)請(qǐng)求做相應(yīng)的處理。常見(jiàn)的是對(duì)model進(jìn)行增加、刪除、查找、修改等。在這部分我們需要實(shí)現(xiàn)ServerViewSet:

class ServerViewSet(viewsets.ModelViewSet):
  """
  物理服務(wù)器視圖
  """
  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,并且按照創(chuàng)建時(shí)間逆序排列,這樣可以把最新的信息先返回,比較符合用戶(hù)的操作習(xí)慣。

serializer_class定義了返回的序列化格式為ServerSerializer所指定的fields內(nèi)容

pagination_class 指定了分頁(yè)的類(lèi)型,這個(gè)MyFormatResultsSetPagination是我們的自定義類(lèi)型

實(shí)現(xiàn)router

如果用戶(hù)想要訪問(wèn)server的信息,需要指定server的路由,這個(gè)和之前介紹的類(lèi)似。需要的嗯一個(gè)一個(gè)router對(duì)象,并且將server的路由注冊(cè)進(jìn)去。

from rest_framework import routers

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

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

對(duì)于servers的訪問(wèn)都由ServerViewSet進(jìn)行處理。

嘗試訪問(wèn)

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

django rest framework中如何實(shí)現(xiàn)數(shù)據(jù)查找、過(guò)濾、排序操作

注:我們需要添加示例信息,作為后續(xù)的各種測(cè)試使用。

按照條件獲取

在日常操作中,我們需要獲取指定條件的數(shù)據(jù),例如對(duì)于物理服務(wù)器,我們需要指定品牌、指定cpu核數(shù)、指定內(nèi)存大小等。有時(shí)候我們需要按照cpu核數(shù)進(jìn)行排序。這些都需要我們對(duì)ServerViewSet進(jìn)行更多的拓展。

如果進(jìn)行條件過(guò)濾,需要首先安裝django-filter模塊:

pip install django-filter

在配置文件settings/base.py中添加應(yīng)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頂部包含如下包:

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

ServerViewSet可以添加相應(yīng)的過(guò)濾條件:

class ServerViewSet(viewsets.ModelViewSet):
  """
  物理服務(wù)器視圖
  """
  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', )

這里的filter_backends指定了過(guò)濾的類(lèi)型,此處設(shè)定了DjangoFilterBackend(過(guò)濾)、SearchFilter(搜索)和OrderingFIlter(排序)。

1.過(guò)濾

過(guò)濾設(shè)定了過(guò)濾的配置類(lèi)為ServerFilter,關(guān)于ServerFilter在apps/assets/filters.py文件中進(jìn)行了定義:

import django_filters

from .models import *


class ServerFilter(django_filters.rest_framework.FilterSet):
  """
  物理服務(wù)器過(guò)濾器
  """

  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', ]

也就是說(shuō)可以通過(guò)'server_name', ‘brand', ‘cpus', ‘ram', ‘disk'對(duì)物理服務(wù)器的信息進(jìn)行過(guò)濾,得到相應(yīng)的序列化列表。

例如獲取cpu為24核的物理服務(wù)器:

django rest framework中如何實(shí)現(xiàn)數(shù)據(jù)查找、過(guò)濾、排序操作

得到物理服務(wù)器列表中cpu都為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 關(guān)鍵字需要查詢(xún)的信息,例如搜索名稱(chēng)為‘test'開(kāi)頭的服務(wù)器:

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

獲取列表:

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中可以指定多種查找方式:

‘^name' 以name開(kāi)頭

‘=name' 精確匹配

‘@' 全局檢索(只有mysql數(shù)據(jù)源支持)

‘$' 正則匹配

對(duì)應(yīng)的search_fileds示例如下:

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

3.排序

在ordering字段指定了默認(rèn)排序方式(按照創(chuàng)建時(shí)間逆序排序):

ordering = ('-created_time', )

也可以使用如下方式指定:

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

如果要自定義排序字段,需要指定 ordering 字段的內(nèi)容:

例如按照內(nèi)存大小排列服務(wù)器:

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

獲取的信息列表如下:

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、過(guò)濾等操作可以組合使用,一般為前端的列表搜索查詢(xún)提供接口支持。

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