#32310: ManyToManyField.through docs clarification
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Reporter: Fabio Sangiovanni | Owner: nobody
Type: Cleanup/optimization | Status: new
Component: Documentation | Version: master
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
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Hello and happy new year everyone!
A note in the current `ManyToManyField.through` docs
(https://docs.djangoproject.com/en/dev/ref/models/fields/#django.db.models.ManyToManyField.through)
suggests that:
> Recursive relationships using an intermediary model and defined as
symmetrical (that is, with symmetrical=True, which is the default) can’t
determine the reverse accessors names, as they would be the same.
But the value of the `symmetrical` argument seems irrelevant in this
regard, since in both cases (`True` or `False` value) the system checks
framework raises the same error (`fields.E304`).
Repro:
{{{
from django.db import models
class Relationship(models.Model):
person1 = models.ForeignKey('Person', on_delete=models.CASCADE)
person2 = models.ForeignKey('Person', on_delete=models.CASCADE)
class Person(models.Model):
other = models.ManyToManyField('self', through=Relationship,
symmetrical=False)
}}}
`manage.py makemigrations` yields:
{{{
SystemCheckError: System check identified some issues:
ERRORS:
app.Relationship.person1: (fields.E304) Reverse accessor for
'Relationship.person1' clashes with reverse accessor for
'Relationship.person2'.
HINT: Add or change a related_name argument to the definition for
'Relationship.person1' or 'Relationship.person2'.
app.Relationship.person2: (fields.E304) Reverse accessor for
'Relationship.person2' clashes with reverse accessor for
'Relationship.person1'.
HINT: Add or change a related_name argument to the definition for
'Relationship.person2' or 'Relationship.person1'.
}}}
for both values of the `symmetrical` argument of `ManyToManyField`.
Am I missing something?
Thanks!
--
Ticket URL: <https://code.djangoproject.com/ticket/32310>
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