Opened 16 years ago
Closed 16 years ago
#7026 closed (fixed)
Exception message is worded poorly (backwards)
Reported by: | Owned by: | nobody | |
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Component: | Database layer (models, ORM) | Version: | dev |
Severity: | Keywords: | models many-to-many manytomany m2m exception primary key pk | |
Cc: | Triage Stage: | Accepted | |
Has patch: | no | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description
This occurs with recent SVN checkout.
(trimmed) example models:
class Tag(models.Model): name = models.CharField(max_length=127, unique=True) class Image(models.Model): tags = models.ManyToManyField(Tag)
code which bombs:
t = Tag(name='foo') t.save() i = Image() i.tags.add(t) #Bombs here because i doesn't have a pk
Traceback File "reloadDB.py", line 73, in ? i.tags.add(t) File "/usr/lib/python2.4/site-packages/django/db/models/fields/related.py", line 485, in __get__ target_col_name=qn(self.field.m2m_reverse_name()) File "/usr/lib/python2.4/site-packages/django/db/models/fields/related.py", line 317, in __init__ raise ValueError("%r instance needs to have a primary key value before a many-to-many relationship can be used." % model) ValueError: <class 'eTrain.models.Tag'> instance needs to have a primary key value before a many-to-many relationship can be used.
The error should indicate the <class 'eTrain.models.Image'> instance doesn't have pk... I'm not sure how to get at this as superclass doesn't seem to have the model attribute set.
Change History (2)
comment:1 by , 16 years ago
Component: | Uncategorized → Database wrapper |
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Triage Stage: | Unreviewed → Accepted |
comment:2 by , 16 years ago
Resolution: | → fixed |
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Status: | new → closed |
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I also ran into this error: I was stumped because I knew that what it was saying was wrong.