Unit 12 associated serialization

One. Default foreign key serialization

1. Now suppose we have two tables

class Teacher(models.Model):tea_name = models.CharField(max_length=20,verbose_name='teacher name')class Meta:verbose_name = 'Teacher table'verbose_name_plural = verbose_namedb_table = 'teacher'def __str__(self):return self.tea_nameclass Student(models.Model):stu_name = models.CharField(max_length=20,verbose_name='student name')score = models.IntegerField(verbose_name='score')sex = models.CharField(max_length=5,verbose_name='sex')teacher = models.ForeignKey(to=Teacher, on_delete=models.CASCADE, verbose_name='Teacher')# teacher's foreign key from table defaults to tea_id, not tea_nameclass Meta:verbose_name = 'student table'verbose_name_plural = verbose_namedb_table = 'student'def __str__(self):return self.stu_name

Our foreign key in the slave table student will generally be displayed as the id of the main table
How to change the foreign key display from id to the content of the binding field of the main table?

2. Module preparation

from rest_framework import serializersfrom student.models import Teacher,Student

1.StringRelated foreign key serialization

Return the __str__ method of the associated table as the result, setting read_only means that the field will not be deserialized and verified
Use the str method of the foreign key table to serialize

class StudentSerializer2(serializers.ModelSerializer):teacher = serializers.StringRelatedField()class Meta:model = Studentfields = '__all__'

2.SlugRelated foreign key serialization

Specified field serialization Changes the content of a field to the content of the specified display field

class StudentSerializer2(serializers.ModelSerializer):teacher = serializers.SlugRelatedField(read_only=True,slug_field='tea_name')class Meta:model = Studentfields = '__all__'

3.PrimaryKeyRelated foreign key serialization

PrimaryKeyRelatedField foreign key serialization, using the primary key of the foreign key table for serialization.Same as the original model serializer

class StudentSerializer2(serializers.ModelSerializer):teacher = serializers.PrimaryKeyRelatedField(read_only=True)class Meta:model = Studentfields = '__all__'

4. Foreign key custom serialization method

Use custom method for serialization, field customization, must be a field in the database (name it yourself)

class StudentSerializer2(serializers.ModelSerializer):tea_name = serializers.SerializerMethodField(read_only=True)# obj is the object of the model classdef get_tea_name(self,obj):return obj.teacher.tea_nameclass Meta:model = Studentfields = '__all__'

2. Deserialization of the associated serializer

The default serializer does not need to write any fields for deserialization. The default association field will accept an id data as a verification basis and create it
To put it bluntly, it is a normal model serializer

class StudentSerializer(serializers.ModelSerializer):class Meta:model = Studentfields = '__all__'