id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
7026	Exception message is worded poorly (backwards)	ryan@…	nobody	"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."		closed	Database layer (models, ORM)	dev		fixed	models many-to-many manytomany m2m exception primary key pk		Accepted	0	0	0	0	0	0