rest_framework-序列化-1

序列化

• 定义模型类

from django.db import models

# Create your models here.

class StuModel(models.Model):
    SEX_CHOICES = (
        (0, '女'),
        (1, '男'),
    )

    name = models.CharField(max_length=10)
    sex = models.SmallIntegerField(choices=SEX_CHOICES, null=True)
    group = models.ForeignKey('Group', on_delete=models.SET_NULL, null=True)
    role = models.ManyToManyField('Roles')

class Group(models.Model):
    name = models.CharField(max_length=10)

class Roles(models.Model):
    name = models.CharField(max_length=10)

• 视图函数

from django.shortcuts import render

# Create your views here.

from rest_framework import serializers
from rest_framework.views import APIView
from .models import *
from django.http import HttpResponse

import json

class MySerializer(serializers.Serializer):
    name = serializers.CharField()  # 普通查询
    sex_field = serializers.IntegerField(source='sex')  # 更改名称查询
    sex = serializers.CharField(source='get_sex_display')  # 内嵌chiose查询
    group = serializers.CharField(source='group.name')  # 关联查询
    rol = serializers.SerializerMethodField()  # manyToMany查询

    def get_rol(self, row):
        queryset = row.role.all()
        resp = []
        for item in queryset:
            resp.append(
                {
                    'id': item.id,
                    'name': item.name
                },
            )
        return resp

class MyView(APIView):

    def get(self, request):
        queryset = StuModel.objects.all()
        serializer = MySerializer(instance=queryset, many=True)
        ret = json.dumps(serializer.data)
        return HttpResponse(ret)

• 自定义序列化对象

  • 自定义的序列化对象必须继承serializers.Serializer
  • 该序列化对象的字段名和类型要和所要系列化的对象的一样
    • 如果要自定义字段名，需要在类型里面加上source=数据库的字段名
    • 多对多查询需要将字段对用成SerializerMethodField的类实例
      
      -定义get_{field_name}的方法，在里面实现自定义的查询
  • 自定义序列化对象实例化时，将所要序列化对象的queryset对象赋值给instance属性，当queryset对象不止一个时，many=True

• 模型序列化对象

class MySerializer(serializers.ModelSerializer):
    # name = serializers.CharField()  # 普通查询
    # sex_field = serializers.IntegerField(source='sex')  # 更改名称查询
    # sex = serializers.CharField(source='get_sex_display')  # 内嵌chiose查询
    group = serializers.CharField(source='group.name')  # 关联查询
    rol = serializers.SerializerMethodField()  # manyToMany查询

    class Meta:
        model = StuModel
        fields = ['name', 'sex_field', 'sex', 'group', 'rol']
        extra_kwargs = {
            'sex_field': {'source': 'sex'},
            'sex': {'source': 'get_sex_display'},
        }

    def get_rol(self, row):
        queryset = row.role.all()
        resp = []
        for item in queryset:
            resp.append(
                {
                    'id': item.id,
                    'name': item.name
                },
            )
        return resp

• 模型序列化需要继承ModelSerializer

• 可以在extra_kwargs定制额外的属性，参考Serializer

• 在Meta里面制定对应的模型和字段，但ModelSerializer只能实现简单的展示，复杂的展示还需要自己定制

• depth：深度追踪

class MySerializer(serializers.ModelSerializer):

    class Meta:
        model = StuModel

        fields = '__all__'
        depth = 1

class MyView(APIView):

    def get(self, request):
        queryset = StuModel.objects.all()
        serializer = MySerializer(instance=queryset, many=True)
        ret = json.dumps(serializer.data)
        return HttpResponse(ret)

在Meta里面加上加上depth = 1，就可以去取它对应的关联表的的下一层的所有数据，depth为几就去找几层