CODEWITHSUNDEEP
djangomany-to-manymodels
Sadie Flick
Sadie Flick

Reputation: 1

Multiple many to many relationships with the same two classes - Django

I have two classes that have two many to many relationships between them. Since the adjoining tables also have to have additional attributes, I explicitly defined them. But I'm getting an error that says I need to change the related names. Not sure where to do this. Any help is greatly appreciated.

Here's my models.py code:

class Client(models.Model):
    first_name = models.CharField(max_length=255)
    last_name = models.CharField(max_length=255)
    email = models.CharField(max_length=255)
    password = models.CharField(max_length=255)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    objects = UserManager()

    def __repr__(self):
        return "<User object: {} {} {} {}>".format(self.first_name, 
self.last_name, self.email, self.password)

class Therapist(models.Model):
    name = models.CharField(max_length=255)
    reviews = models.ManyToManyField(Client, through="Review")
    appts = models.ManyToManyField(Client, through="Appointment")
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    objects = UserManager()

    def __repr__(self):
        return "<Book object: {}>".format(self.title)



class Review(models.Model):
    reviewer = models.ForeignKey(Client, on_delete=models.CASCADE)
    therapist_reviewed = models.ForeignKey(Therapist, 
on_delete=models.CASCADE)
    rating = models.IntegerField()
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    content = models.TextField()

    def __repr__(self):
        return "<Review object: {} {}>".format(self.book_reviewed, 
self.reviewer)

class Appointment(models.Model):
    booked_therapist = models.ForeignKey(Therapist, 
on_delete=models.CASCADE)
    booked_client = models.ForeignKey(Client, on_delete=models.CASCADE)
    date = models.DateTimeField()
    massage = models.CharField(max_length=255)

Upvotes: 0

Views: 1091

Answers (1)

Ykh
Ykh

Reputation: 7717

class Therapist(models.Model):
    name = models.CharField(max_length=255)
    reviews = models.ManyToManyField(Client, related_name='therapist_reviews', through="Review")
    appts = models.ManyToManyField(Client, related_name='therapist_appts', through="Appointment")
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    objects = UserManager()

    def __repr__(self):
        return "<Book object: {}>".format(self.title)

If you don't assign related_name for many_to_many field,the default related will set to model_lower_case_set,but when you has two many_to_many fields related to one same model,the default related_name for the two fileds is same as model_lower_case_set,this will cause conflict when use related_name to query queryset.

Upvotes: 2

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