Django REST framweork

INSTALLED_APPS = [
....
‘rest_framework‘,
]

from django.db import models

# Create your models here.


class Classg(models.Model):
    cname = models.CharField(max_length=20)
    number = models.IntegerField()
    teacher = models.ManyToManyField(‘Teacher‘, related_name=‘tracks‘)


class Studnet(models.Model):
    sname = models.CharField(max_length=20)
    age = models.IntegerField()
    sex = models.BooleanField(default=0)
    classg = models.ForeignKey(‘Classg‘, related_name=‘tracks‘, on_delete=None)
    course = models.OneToOneField(‘Course‘, on_delete=None)


class Course(models.Model):
    cname = models.CharField(max_length=20)


class Teacher(models.Model):
    tname = models.CharField(max_length=20)
    

# 在本项目的根目录的终端进行同步迁移：

1. python3 manage.py migrate
2. python3 manage.py makemigrations
3. python3 manage.py migrate

import os, django
#  外部调用 Django models
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "proj.settings")
django.setup()
from  celeryapp01.models import *
import sys


c1 = Classg.objects.create(cname=‘三年级一班‘, number=30)
c2 = Classg.objects.create(cname=‘三年级二班‘, number=60)


s1 = Course.objects.create(cname=‘数学‘)
s2 = Course.objects.create(cname=‘语文‘)

st1 = Studnet.objects.create(sname=‘张三‘, age=28, sex=1, classg=c1, course=s1)
st2 = Studnet.objects.create(sname=‘李四‘, age=29, sex=0, classg=c2, course=s2)

t1 = Teacher.objects.create(tname=‘比利‘)
t2 = Teacher.objects.create(tname=‘许Var强‘)

# 多对多正向插入
c1.teacher.add(t1)
c2.teacher.add(t2)

from rest_framework import serializers
from celeryapp01 import models

class StudentSerizlizer(serializers.HyperlinkedModelSerializer):
    class Meta:
        model = models.Studnet
        fields = (‘sname‘, ‘age‘, ‘sex‘,)  # 这里将 你所想展示出来的字段

from rest_framework import viewsets
from celeryapp01 import models
from celeryapp01.rest_serializer import StudentSerizlizer


class StudentViewSet(viewsets.ModelViewSet):
    queryset = models.Studnet.objects.all()
    serializer_class = StudentSerizlizer

from django.contrib import admin
from django.urls import path,include
urlpatterns = [
    path(‘admin/‘, admin.site.urls),
    path(r‘celeryapp01/‘, include(‘celeryapp01.api_urls‘)),
]

from django.urls import path,include
from celeryapp01 import views
from rest_framework import routers
from celeryapp01.rest_views import StudentViewSet
router = routers.DefaultRouter()
router.register(r‘students‘, StudentViewSet)

urlpatterns = [
    path(r‘api/‘, include(router.urls)),
]
# 逻辑关系

# 一对一，一个学生对应一个总分表的行对象
class StudentSerizlizer(serializers.HyperlinkedModelSerializer):
    cname = serializers.CharField(source=‘course.cname‘) # 查询与之关联的一对一关系字段

    class Meta:
        model = models.Studnet
        fields = (‘sname‘, ‘age‘, ‘sex‘, ‘cname‘)


class CourseSerizlizer(serializers.HyperlinkedModelSerializer):

    class Meta:
        model = models.Course
        fields = (‘cname‘,)

class StudentViewSet(viewsets.ModelViewSet):
    queryset = models.Studnet.objects.all()
    serializer_class = StudentSerizlizer
    
    
class CourseViewSet(viewsets.ModelViewSet):
    queryset = models.Course.objects.all()
    serializer_class = CourseSerizlizer

router.register(r‘students‘, StudentViewSet)
router.register(r‘courses‘, CourseViewSet)

class ClassgSerizlizer(serializers.HyperlinkedModelSerializer):
    tracks = serializers.StringRelatedField(many=True)  # 一对多

    class Meta:
        model = models.Classg
        fields = (‘cname‘, ‘number‘, ‘tracks‘)

class TeacherSerizlizer(serializers.HyperlinkedModelSerializer):
    tracks = serializers.PrimaryKeyRelatedField(many=True, read_only=True)  # 多对多
    class Meta:
        model = models.Teacher
        fields = (‘tname‘,‘tracks‘)

class ClassgViewSet(viewsets.ModelViewSet):
    queryset = models.Classg.objects.all()
    serializer_class = ClassgSerizlizer

class TeacherViewSet(viewsets.ModelViewSet):
    queryset = models.Teacher.objects.all()
    serializer_class = TeacherSerizlizer

class ClassgSerizlizer(serializers.HyperlinkedModelSerializer):
    tracks = serializers.StringRelatedField(many=True)  # 一对多必须要添加这行代码

    class Meta:
        model = models.Classg
        fields = (‘cname‘, ‘number‘, ‘tracks‘)


class StudentSerizlizer(serializers.HyperlinkedModelSerializer):
    cname = serializers.CharField(source=‘course.cname‘)  # 查询与之相关联的行对象

    class Meta:
        model = models.Studnet
        fields = (‘sname‘, ‘age‘, ‘sex‘, ‘cname‘)

class ClassgViewSet(viewsets.ModelViewSet):
    queryset = models.Classg.objects.all()
    serializer_class = ClassgSerizlizer


class TeacherViewSet(viewsets.ModelViewSet):
    queryset = models.Teacher.objects.all()
    serializer_class = TeacherSerizlizer

1.具有一对多、多对多关系的model，也想序列化，必须要在关联字段里添加参数 ：related_name=‘tracks‘  如：
                                                            classg = models.ForeignKey(‘Classg‘, related_name=‘tracks‘, on_delete=None)

2. 

tracks = serializers.StringRelatedField(many=True) #一对多

tracks = serializers.PrimaryKeyRelatedField(many=True, read_only=True) # 多对多

这两个序列化字段很有意思，如：A表和B表关系为一对多，模型的字典字段定义在B表，那么tracks = serializers.StringRelatedField(many=True) 必须写在B序列化的类里
多对多也是如此。