CODEWITHSUNDEEP
pythondjangodjango-modelsmany-to-many
Cédric Rémond
Cédric Rémond

Reputation: 1054

Django : ManyToMany relation error ( object has no attribute)

I am trying to define some ManyToMany relations in Django, but I have an error when I try to create related objects.

My models.py :

class PerfumeBrand(models.Model):
    class Meta:
        verbose_name = "Marque de parfum"
        verbose_name_plural = "Marques de parfum"

    name = models.CharField(max_length=32)

    def __str__(self):
        return self.person.first_name + ' ' +  self.person.last_name.upper() + ': ' + self.name


class Person(models.Model):
    class Meta:
        verbose_name = "Personne"
        verbose_name_plural = "Personnes"

    first_name = models.CharField(max_length=32, )
    last_name = models.CharField(max_length=32)
    email = models.EmailField(unique=True)
    # Here is the ManyToMany relation
    perfume_brands = models.ManyToManyField(PerfumeBrand)

The problem is that when I try to save a PerfumeBrand object in my database, I get this error :

AttributeError at /admin/visualize/perfumebrand/add/

'PerfumeBrand' object has no attribute 'person'

I tried to save both in code and admin panel, the same error occurs.

As this is the first time I need a ManyToMany relation in a Django project, I am a bit confused, and I didn't find any solution to my problem.

Have you any idea ?

Upvotes: 1

Views: 2068

Answers (2)

VMRuiz
VMRuiz

Reputation: 1981

On the PerfumeBrand object, you have declared this 

def __str__(self):
    return self.person.first_name + ' ' + self.person.last_name.upper() + ': ' + self.name

But person is not an attribute of PerfumeBrand. That function should be under the Person class (with some changes before) and you should use something like the following in the PerfumeBrand class:

def __str__(self):
    return self.name

Upvotes: 1

tactic
tactic

Reputation: 57

The class PerfumeBrand never defines the variable person, only name.

Upvotes: 1

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