공감 기능 구현과 one-to-one/many, many-to-one/many 관계

one-to-one, one-to-many, manytoone, manytomany

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one-to-one

• OneToOneField 사용

one-to-many 

• 접합/중개 모델을 사용하여 일대 다 관계 표현

class Number(models.Model):
    number = models.CharField(max_length = 10)

class Person(models.Model):
    name = models.CharField(max_length = 200)
    
class PersonNumber(models.Model):
    person = models.ForeignKey(Person, on_delete = models.CASCADE, related_name = "numbers")
    number = models.ForeignKey(Number, on_delete = models.CASCADE, related_name = "person")

• 외래키를 이용하여 일대 다 관계 표현 

class Person(models.Model):
    name = models.CharField(max_length = 200)

class Number(models.Model):
    person = models.ForeignKey(Person, on_delete = models.CASCADE)
    number = models.CharField(max_length = 10)