ORM🏹: 장고 Abstract Models

# ./products/models.py
from django.db import models


class AbstractCar(models.Model):
    manufacturer = models.ForeignKey('Manufacturer', on_delete=models.CASCADE)

    class Meta:
        abstract = True

메타 클래스에 "abstract = True"이면 migrate하더라도
DB에 물리테이블이 생기지 않는다!
왜냐면 추상 테이블이 되었기 때문이다!

# ./proudction/models.py
from django.db import models
from products.models import AbstractCar


class Manufacturer(models.Model):
    pass


class Car(AbstractCar):
    pass

위의 모델을 migrate해서 생성된 테이블

• production_car
  CREATE TABLE "production_car" ("id" integer NOT NULL PRIMARY KEY AUTOINCREMENT, "manufacturer_id" integer NOT NULL REFERENCES "production_manufacturer" ("id") DEFERRABLE INITIALLY DEFERRED)
  => "production_car" 테이블은 상속받은 "AbstractCar"에서 정의 된 컬럼과 같당!
• production_manufacturer
  CREATE TABLE "production_manufacturer" ("id" integer NOT NULL PRIMARY KEY AUTOINCREMENT)
• 주의!! product_abstractcar 테이블은 생성되지 않았다! 왜냐하면 AbstractCar는 추상클래스로 설정되어 있기 때문이다!

Reference

• https://docs.djangoproject.com/en/3.1/ref/models/fields/#django.db.models.ForeignKey