ModelSerializer序列化器实战

ModelSerializer序列化器实战 使用ModelSerializer序列化器如何写接口?这里源码demo都写全了~一看就懂!

ModelSerializer序列化器实战

经历了源码的痛苦,掌握DRF的核心序列化器

上篇ModelSerializer序列化器做了一个小demo,演示了如何操作单表进行序列化和反序列化来实现五个API的使用,多表大差不差,这里对四个表写五个API接口

单表操作

单表操作序列化类demo:

序列化器类

# ModelSerializer和表模型有绑定关系
class BookSerializer1(serializers.ModelSerializer):
    class Meta:
        model = Book  # 指定和哪个表有关系
        # 所有字段
        # fields = '__all__'
        # 这里注意id字段是从表模型映射过来的,auto自增的,不传也可以
        # 自定制的字段不传必须注册,在列表中
        fields = ['id', 'title', 'price', 'price_info']  # 指定字段
        extra_kwargs = {
            'title': {'write_only': True, 'max_length': 8, 'min_length': 3}
        }
    # 指定序列化的字段:两种写法:在序列化类中写;models中写
    price_info = serializers.SerializerMethodField()
    def get_price_info(self, obj):
        return "价格是:" + str(obj.price)
    '''
    注意:自定制字段如果和表模型获取到的字段是同名,那么自定制返回给前端的字段值就被自定制覆盖了,比如:
    title = serializers.SerializerMethodField()
    def get_title(self, obj):
        return "书名是:" + str(obj.title)
    '''

    #  局部和全局钩子,跟之前一样,但是要注意写在Meta外

视图类

from rest_framework.views import APIView
from .models import Book
from rest_framework.response import Response
from app01.serializer import  BookSerializer1
class BookView1(APIView):
    def get(self, request):
        # 从数据库查数据,做序列化
        book_list = Book.objects.all()
        # 实例化类,传入初始化的参数,instance和many
        '''
        instance:要序列化的对象  qs,单个对象
        many:如果是qs对象,many=True,如果是单个对象many=False
        '''
        ser = BookSerializer1(instance=book_list, many=True)
        # ser.data使用模型类的对象得到序列化后的字典
        return Response(ser.data)

    def post(self,request):
        # 反序列化,保存到数据库使用data参数
        deser = BookSerializer1(data=request.data)
        # 校验数据
        if deser.is_valid():
            # 保存需要重写create方法,不然不知道存到哪个表
            deser.save()
            return Response(deser.data)
        return Response({'code':101,'msg':'校验不通过','errors':deser.errors})



# 处理修改再写一个视图类,防止get冲突
class BookDetailView1(APIView):
    def get(self,request,pk):
        book = Book.objects.filter(pk=pk).first()
        ser = BookSerializer1(instance=book)  # 这里设置了主键值,单条记录many不需要写
        return Response(ser.data)
    def delete(self,request,pk):
        res = Book.objects.filter(pk=pk).delete()
        print(res) # (1, {'app01.Book': 1})
        # res是影响的行数
        if res[0]>0:
            return Response({'code': 100, 'msg': '删除成功'})
        else:
            return  Response({'code': 103, 'msg': '要删除的数据不存在'})

    # 反序列化修改
    def put(self,request,pk):
        # 修改处理单条数据用过pk确定求改哪条数据
        book = Book.objects.filter(pk=pk).first()
        # 序列化器类实例化需要传入instance,data才表示修改
        ser = BookSerializer1(instance=book,data=request.data)
        if ser.is_valid():
            # 重写update方法才能存入
            ser.save()
            return Response(ser.data)
        return Response({'code':101,'msg':'校验未通过','error':ser.errors})

路由

path('books1/', views.BookView1.as_view()),
path('books1/<int:pk>', views.BookDetailView1.as_view()),

模型

from django.db import models
class Book(models.Model):
    title = models.CharField(max_length=32)
    price = models.DecimalField(max_digits=5,decimal_places=2)
    authors = models.CharField(max_length=32)

多表操作

models.py

from django.db import models



# build four model tables

class Book(models.Model):
    name = models.CharField(max_length=32)
    price = models.DecimalField(decimal_places=2, max_digits=5)
    publish = models.ForeignKey(to='Publish', on_delete=models.CASCADE)
    authors = models.ManyToManyField(to='Author')

    def __str__(self):
        return self.name

    # 自定制字段
    @property
    def publish_detail(self):
        return {'name': self.publish.name, 'addr': self.publish.city}

    @property
    def author_list(self):
        l = []
        print(self.authors.all()) # <QuerySet [<Author: Author object (1)>, <Author: Author object (2)>]>
        for author in self.authors.all():
            print(author.author_detail) # AuthorDetail object (1)
            l.append({'name': author.name, 'age': author.age, 'addr': author.author_detail.addr})
        return l


class Author(models.Model):
    name = models.CharField(max_length=32)
    age = models.IntegerField()
    author_detail = models.OneToOneField(to='AuthorDetail', on_delete=models.CASCADE)

    def __str__(self):
        return self.name

    @property
    def authordetail_info(self):
        return {'phone':self.author_detail.telephone,'addr':self.author_detail.addr}


class AuthorDetail(models.Model):
    telephone = models.BigIntegerField()
    addr = models.CharField(max_length=64)


class Publish(models.Model):
    name = models.CharField(max_length=32)
    city = models.CharField(max_length=32)
    email = models.EmailField()

serializer.py

from app01 import models
from rest_framework import serializers


# 书序列化器
class BookSerializer(serializers.ModelSerializer):
    class Meta:
        # 指定和哪个表有关系
        model = models.Book
        # fields = '__all__'
        fields = ['id','name','price','publish','authors','publish_detail','author_list']
        # 将关联表的信息全部取出来,不推荐使用
        # depth = 1

        extra_kwargs = {
            'publish':{'write_only':True},
            'authors':{'write_only':True}
        }

# 作者序列化器
class AuthorSerializer(serializers.ModelSerializer):
    class Meta:
        # 指定和哪个表有关系
        model = models.Author
        # fields = '__all__'
        fields = ['id', 'name', 'age', 'author_detail', 'authordetail_info']
        extra_kwargs = {
            'author_detail': {'write_only': True},
        }


# 作者详情序列化器
class AuthorDetailSerializer(serializers.ModelSerializer):
    class Meta:
        # 指定和哪个表有关系
        model = models.AuthorDetail
        fields = '__all__'

# 出版社序列化器
class PublishSerializer(serializers.ModelSerializer):
    class Meta:
        # 指定和哪个表有关系
        model = models.Publish
        fields = '__all__'

views.py

from rest_framework.response import Response
from rest_framework.views import APIView

from app01 import models
from app01 import serializer


# 书视图类
class BookView(APIView):
    def get(self, requets):
        # 序列化
        book_list = models.Book.objects.all()
        # 序列化多条数据many=True
        ser = serializer.BookSerializer(instance=book_list, many=True)
        return Response(ser.data)

    def post(self, request):
        # 获取反序列化数据
        ser = serializer.BookSerializer(data=request.data)
        if ser.is_valid():
            # 校验通过存入数据库,不需要重写create方法了
            ser.save()
            return Response({'code': 100, 'msg': '新增成功', 'data': ser.data})
        # 校验失败
        return Response({'code': 101, 'msg': '校验未通过', 'error': ser.errors})


class BookViewDetail(APIView):
    def get(self, request, pk):
        book = models.Book.objects.filter(pk=pk).first()
        ser = serializer.BookSerializer(instance=book)
        return Response(ser.data)

    def put(self, request, pk):
        book = models.Book.objects.filter(pk=pk).first()
        # 修改,instance和data都要传
        ser = serializer.BookSerializer(instance=book, data=request.data)
        if ser.is_valid():
            # 校验通过修改,不需要重写update
            ser.save()
            return Response({'code:': 100, 'msg': '修改成功', 'data': ser.data})
        # 校验不通过
        return Response({'code:': 102, 'msg': '校验未通过,修改失败', 'error': ser.errors})

    def delete(self, request, pk):
        models.Book.objects.filter(pk=pk).delete()
        return Response({'code': 100, 'msg': '删除成功'})


# 作者视图类
class AuthorView(APIView):
    def get(self, requets):
        # 序列化
        author_list = models.Author.objects.all()
        # 序列化多条数据many=True
        ser = serializer.AuthorSerializer(instance=author_list, many=True)
        return Response(ser.data)

    def post(self, request):
        # 获取反序列化数据
        ser = serializer.AuthorSerializer(data=request.data)
        if ser.is_valid():
            # 校验通过存入数据库,不需要重写create方法了
            ser.save()
            return Response({'code': 100, 'msg': '新增成功', 'data': ser.data})
        # 校验失败
        return Response({'code': 101, 'msg': '校验未通过', 'error': ser.errors})


class AuthorViewDetail(APIView):
    def get(self, request, pk):
        book = models.Author.objects.filter(pk=pk).first()
        ser = serializer.AuthorSerializer(instance=book)
        return Response(ser.data)

    def put(self, request, pk):
        book = models.Author.objects.filter(pk=pk).first()
        # 修改,instance和data都要传
        ser = serializer.AuthorSerializer(instance=book, data=request.data)
        if ser.is_valid():
            # 校验通过修改,不需要重写update
            ser.save()
            return Response({'code:': 100, 'msg': '修改成功', 'data': ser.data})
        # 校验不通过
        return Response({'code:': 102, 'msg': '校验未通过,修改失败', 'error': ser.errors})

    def delete(self, request, pk):
        models.Author.objects.filter(pk=pk).delete()
        return Response({'code': 100, 'msg': '删除成功'})


# 作者详情视图类
class AuthorDetailView(APIView):
    def get(self, requets):
        # 序列化
        author_list = models.AuthorDetail.objects.all()
        # 序列化多条数据many=True
        ser = serializer.AuthorDetailSerializer(instance=author_list, many=True)
        return Response(ser.data)

    def post(self, request):
        # 获取反序列化数据
        ser = serializer.AuthorDetailSerializer(data=request.data)
        if ser.is_valid():
            # 校验通过存入数据库,不需要重写create方法了
            ser.save()
            return Response({'code': 100, 'msg': '新增成功', 'data': ser.data})
        # 校验失败
        return Response({'code': 101, 'msg': '校验未通过', 'error': ser.errors})


class OneAuthorViewDetail(APIView):
    def get(self, request, pk):
        book = models.AuthorDetail.objects.filter(pk=pk).first()
        ser = serializer.AuthorDetailSerializer(instance=book)
        return Response(ser.data)

    def put(self, request, pk):
        book = models.AuthorDetail.objects.filter(pk=pk).first()
        # 修改,instance和data都要传
        ser = serializer.AuthorDetailSerializer(instance=book, data=request.data)
        if ser.is_valid():
            # 校验通过修改,不需要重写update
            ser.save()
            return Response({'code:': 100, 'msg': '修改成功', 'data': ser.data})
        # 校验不通过
        return Response({'code:': 102, 'msg': '校验未通过,修改失败', 'error': ser.errors})

    def delete(self, request, pk):
        models.AuthorDetail.objects.filter(pk=pk).delete()
        return Response({'code': 100, 'msg': '删除成功'})

# 出版社视图类
class PublishView(APIView):
    def get(self, requets):
        # 序列化
        author_list = models.Publish.objects.all()
        # 序列化多条数据many=True
        ser = serializer.PublishSerializer(instance=author_list, many=True)
        return Response(ser.data)

    def post(self, request):
        # 获取反序列化数据
        ser = serializer.PublishSerializer(data=request.data)
        if ser.is_valid():
            # 校验通过存入数据库,不需要重写create方法了
            ser.save()
            return Response({'code': 100, 'msg': '新增成功', 'data': ser.data})
        # 校验失败
        return Response({'code': 101, 'msg': '校验未通过', 'error': ser.errors})


class PublishViewDetail(APIView):
    def get(self, request, pk):
        book = models.Publish.objects.filter(pk=pk).first()
        ser = serializer.PublishSerializer(instance=book)
        return Response(ser.data)

    def put(self, request, pk):
        book = models.Publish.objects.filter(pk=pk).first()
        # 修改,instance和data都要传
        ser = serializer.PublishSerializer(instance=book, data=request.data)
        if ser.is_valid():
            # 校验通过修改,不需要重写update
            ser.save()
            return Response({'code:': 100, 'msg': '修改成功', 'data': ser.data})
        # 校验不通过
        return Response({'code:': 102, 'msg': '校验未通过,修改失败', 'error': ser.errors})

    def delete(self, request, pk):
        models.Publish.objects.filter(pk=pk).delete()
        return Response({'code': 100, 'msg': '删除成功'})

urls.py

from django.contrib import admin
from django.urls import path

from app01 import views

urlpatterns = [
    path('admin/', admin.site.urls),
    # 书
    path('books/', views.BookView.as_view()),
    path('books/<int:pk>', views.BookViewDetail.as_view()),

    # 作者
    path('authors/', views.AuthorView.as_view()),
    path('authors/<int:pk>', views.AuthorViewDetail.as_view()),

    # 作者详情
    path('authorsdetail/', views.AuthorDetailView.as_view()),
    path('authorsdetail/<int:pk>', views.OneAuthorViewDetail.as_view()),

    # 出版社
    path('publish/', views.PublishView.as_view()),
    path('publishdetail/<int:pk>', views.PublishViewDetail.as_view()),
]

image

优化操作

我们知道作者表和作者详情表的表关系是一对一的关系,那么新增数据的时候,就得先新增作者详情表,再增作者表的数据,但是在实际生活中,用户不知道表关系这码事,为了体验更好,可以重写create方法,同时存两个表的内容,给用户的感觉就是操作了一张表

'''优化作者表的序列化器'''
# 作者序列化器
class AuthorSerializer(serializers.ModelSerializer):
    class Meta:
        # 指定和哪个表有关系
        model = models.Author
        # fields = '__all__'
        fields = ['id', 'name', 'age', 'telephone', 'addr','authordetail_info']

    # 重写字段telephone和addr
    telephone = serializers.CharField(write_only=True)
    addr = serializers.CharField(write_only=True,max_length=8,required=False)


    # 重写create,操作两个表
    def create(self, validated_data):
        # 先存作者详情
        authordetail = models.AuthorDetail.objects.create(telephone=validated_data.get('telephone'),addr=validated_data.get('addr'))
        # 存作者表
        author = models.Author.objects.create(author_detail=authordetail,name=validated_data.get('name'),age=validated_data.get('age'))
        # 这样只返回author对象就行,直接存了两个表,返回反序列化的对象
        return author

image
image

Postman自行测试,我测了测都能用,有问题望指正~

注意
如果实际项目中不需要操作数据库可以使用APIView,如果操作数据库那么推荐使用GenericAPIView