Django project - realize API access through APIView, add, delete, modify and check database

premise

This article is modified on the basis of existing projects
https://blog.csdn.net/qq_38122800/article/details/128583379?spm=1001.2014.3001.5502

1. Configure the serializer

The serializer includes two processes of serialization and deserialization. The simple understanding is

Serialization : Change the data checked from the database into json data acceptable to the front-end page.
Deserialization : Change the data passed in from the front-end into model data, which is usually used for data verification at the back-end. This article does not involve this part.
Create a new serializers.py file under DjangoProject2 (the file name is random)

code:

from demo.models import Person   #导入数据表模型
from rest_framework import serializers   

class PersonModelSerializer(serializers.ModelSerializer):
    class Meta:
        model = Person
        fields = "__all__"

2. Install Django Rest Framework

Execute command in terminal

pip3 install djangorestframework

Then go to the settings.py file to modify INSTALLED_APPS and configure rest_framework

code:

INSTALLED_APPS = [
    "django.contrib.admin",
    "django.contrib.auth",
    "django.contrib.contenttypes",
    "django.contrib.sessions",
    "django.contrib.messages",
    "django.contrib.staticfiles",
    "rest_framework",  #Django-Rest Framework是以Django扩展应用的方式提供的
    "demo"
]

3. Realize the interface function

With the same interface, the function of inserting data is realized through post access , and the function of querying data is realized through get access

Open the view.py file

import module

from rest_framework.views import APIView  #视图
from rest_framework.response import Response  #响应
from demo.models import Person   #数据表模型
from djangoProject2.serializers import PersonModelSerializer   #序列化器
from rest_framework import status   #接口状态码

Define the functionality implemented by the interface

Create a new class that inherits from APIView

Let me explain here that when inserting data, use create to insert data

obj= Person.objects.create(first_name = first_name,last_name = last_name)

However, this usage needs to specify the corresponding value of each field, so update_or_create() is used. This method can directly write the entire json string after defaults. Specific usage:

update_or_create(defaults=None, **kwargs)

执行规则: filter kwargs，create/update defaults
返回值为元组: (object, created)，object为新建或者更新的对象，created为一个布尔值，表示是新建还是更新，True为新建

Interface code:

class RecordList(APIView):
    res = {
    
    
        'code': status.HTTP_200_OK,
        'data':None,
        'msg': 'success',
    }
    
    #通过post请求时，实现插入数据的功能
    def post(self,request):
        #获取前端传入的请求体数据
        first_name = request.POST.get('first_name')
        last_name = request.POST.get('last_name')

        data = {
    
    
            'first_name':first_name,
            'last_name': last_name,
        }
        print("data>>>>>>",data)

        #update_or_create需要提供一个查询参数，先查询，如果不存在，则插入，如果存在，则更新。这里设置id为None,可以达到直接插入的效果
        obj,iscreated= Person.objects.update_or_create(defaults=data,id=None)
        print("插入结果>>>>>>>",obj)
        return Response(self.res)

    #通过get请求时，实现查询数据库并返回给接口的功能
    def get(self,request):
        #获取接口传入的数据
        first_name = request.GET.get('first_name')
        #根据first_name查询数据库
        data_obj = Person.objects.filter(first_name=first_name)

        #data_obj>>>>>> <class 'django.db.models.query.QuerySet'> <QuerySet [<Person: Person object (5)>]>
        print('data_obj>>>>>>',type(data_obj),data_obj)

        #实例化序列器
        ser = PersonModelSerializer(instance=data_obj,many = True)

        #获取序列化后的数据
        self.res['data'] = ser.data

        # 将数据返给接口
        return Response(self.res)
	#删除数据
    def delete(self, request):
        first_name = request.GET.get('first_name')
        obj = Person.objects.filter(first_name = first_name).delete()
        self.res['data'] = obj
        return Response(self.res)

4. Configure routing

Configure routing in the demo/urls.py file to correspond to the interface function written in step 3

code:

urlpatterns = [
    path("recordlist",views.RecordList.as_view). #接口地址:127.0.0.1:8000/st/recordlist
]

5. Use the postman request interface to verify the effect

insert data

First_name and last_name are added to the form, and the interface returns code200, indicating that the interface access is successful

Curl content, copied to posrman available

curl --location --request POST 'http://127.0.0.1:8000/st/recordlist' \
--form 'first_name="f"' \
--form 'last_name="l1234"'

Enter the database, you can see the inserted data

Query data

The interface is still: http://127.0.0.1:8000/st/recordlist
Access method: get
adds first_name as f in the parameter, to query the data in the database whose first_name is f, you can see that the interface returns all the queried data

Curl content, copied to posrman available

curl --location --request GET 'http://127.0.0.1:8000/st/recordlist?first_name=f'