Django Rest Framework Association Relationship--serializer Relations__django

Turn from: http://django-rest-framework.org/api-guide/relations.html

Serializer Relations

Bad programmers worry about the code. Good programmers worry about data structures and their relationships.

-linus Torvalds

Relational fields are used to represent model relationships. They can be applied to ForeignKey, Manytomanyfield andonetoonefield relationships, as-as-to-reverse relationships, an D custom relationships such as Genericforeignkey.

Note: The relational fields are declared in relations.py, but by convention your should import them from the Serializersmodule, u Sing from rest_framework import serializers and refer to fields as Serializers.<fieldname>. API Reference

In order to explain the various types of relational fields, we'll use a couple of simple models for our examples. Our models would be a for music albums, and the tracks listed on each album.

Class Album (models. Model):
    album_name = models. Charfield (max_length=100)
    artist = models. Charfield (max_length=100)

class Track (models. Model):
    album = models. ForeignKey (Album, related_name= ' tracks ') Order
    = models. Integerfield ()
    title = models. Charfield (max_length=100)
    duration = models. Integerfield ()

    class Meta:
        Unique_together = (' album ', ' Order ')
        order_by = ' the '

    Self): Return
        '%d:%s '% (Self.order, self.title)

Relatedfield

Relatedfield May is used to represent the target of the relationship using it ' s __unicode__ method.

For example, the following serializer.

Class Albumserializer (serializers. Modelserializer):
    tracks = Relatedfield (many=true)

    class Meta:
        model = Album
        fields = (' Album_name ', ' Artist ', ' tracks ')

Would serialize to the following representation.

{
    ' album_name ': ' Things We Lost in the Fire ',
    ' Artist ': ' Low '
    tracks ': [
        ' 1:sunflower ',
        ' 2: Whitetail ',
        ' 3:dinosaur Act ',
        ...
    ]
}

This field is read only.

Arguments: Many-if applied to a to-many relationship, your should set this argument to True. Primarykeyrelatedfield

Primarykeyrelatedfield May is used to represent the target of the relationship using it ' s primary key.

For example, the following serializer:

Class Albumserializer (serializers. Modelserializer):
    tracks = Primarykeyrelatedfield (Many=true, read_only=true)

    class Meta:
        model = Album
        fields = (' Album_name ', ' Artist ', ' tracks ')

Would serialize to a representation as this:

{
    ' album_name ': ' The Roots ', '
    artist ': ' Undun '
    tracks ': [M
        , N
        , M
        ,
        ...
    ]
}

By default This field is Read-write, although your can change this behavior using the READ_ONLY flag.

Arguments: Many-if applied to a to-many relationship, your should set this argument to True. Required-if set to False, the field would accept values of None or the empty-string for nullable relationships. Queryset-by default Modelserializer classes would use the default queryset for the relationship. Serializer classes must either set a Queryset explicitly, or set read_only=true. Hyperlinkedrelatedfield

Hyperlinkedrelatedfield May is used to represent the target of the relationship using a hyperlink.

For example, the following serializer:

class Albumserializer (serializers. Modelserializer): tracks = Hyperlinkedrelatedfield (Many=true, Read_only=true, Vie W_name= ' Track-detail ') class Meta:model = Album fields = (' Album_name ', ' Artist ', ' tracks '