Opened 17 years ago
Closed 17 years ago
#6758 closed (invalid)
Multiple 'self' referencing ManyToManyFields in one model overwrite each other's data
Reported by: | notanumber | Owned by: | nobody |
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Component: | Database layer (models, ORM) | Version: | dev |
Severity: | Keywords: | ManyToManyField, self, multiple | |
Cc: | Triage Stage: | Unreviewed | |
Has patch: | no | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description
Defining multiple ManyToManyFields in one model is problematic. When updating one field, all of the others are updated with the same data.
For example, in the following model:
from django.db import models class Job(models.Model): title = models.CharField(max_length=100) reports_to = models.ManyToManyField('self', null=True, blank=True, related_name='reports_to_set') supervises = models.ManyToManyField('self', null=True, blank=True, related_name='supervises_set') class Admin: pass def __unicode__(self): return self.title
Updating a user's data, "Bill", 'reports_to' to read "John", also sets 'supervises' to "John" as well. Obviously, in this case at least, this is not the desired behaviour.
Adding symmetrical=False does not correct this issue, but raises another: When updating "Bill" to 'reports_to' "John", we end up with both users having "John" & "Bill" in their 'reports_to' & 'supervises' fields.
Tested this on WindowsXP, using SQLite3 & the built-in 'runserver' command.
The test application & project is attached to this ticket. The admin user/password is "test"/"test123"
Attachments (1)
Change History (3)
by , 17 years ago
Attachment: | testm2m.zip added |
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comment:1 by , 17 years ago
I'm unable to replicate any of the problems here. I never have the reports_to field being updated when the supervises field is set, or vice-versa. I also always have the various many-to-many fields containing exactly the information I set them to. This is the same whether I use the shell or the admin interface (using trunk's subversion code).
Can you please give step-by-step instructions starting from a clean database of how you create even one of these problems.
comment:2 by , 17 years ago
Resolution: | → invalid |
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Status: | new → closed |
Hmmm. I can't seem to replicate this issue myself, anymore.
Maybe it was a side effect of something else? Guess I'll withdraw this bug.
Test appliction and project