#25486: ORM generating incorrect query for through-model on
<RelatedManager>.all()
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Reporter: pembo13 | Owner: nobody
Type: Bug | Status: new
Component: Database layer (models, ORM) | Version: 1.8
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Easy pickings: 0 | UI/UX: 0
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I have a through-model which itself has a through model (because it needs
a many-to-many relationship). The problem comes when i try to get related
mode through this many-to-many relationship. The ORM generates the WHERE
clause on the wrong field (the pk, instead of the fk).
{{{
#!sql
-- generated sql
SELECT "core_role"."id", "core_role"."name"
FROM "core_role"
INNER JOIN "core_dealercontactrole" ON ( "core_role"."id" =
"core_dealercontactrole"."role_id" )
WHERE "core_dealercontactrole"."id" = 8743
ORDER BY "core_role"."name" ASC
-- corrected sql
SELECT "core_role"."id", "core_role"."name"
FROM "core_role"
INNER JOIN "core_dealercontactrole" ON ( "core_role"."id" =
"core_dealercontactrole"."role_id" )
WHERE "core_dealercontactrole"."dealercontact_id" = 8743
ORDER BY "core_role"."name" ASC
}}}
The code that generated the query:
{{{
#!python
dc = DealerContact.objects.get(id=8743)
>>> unicode(dc.roles.all().query)
u'SELECT "core_role"."id", "core_role"."name" FROM "core_role" INNER JOIN
"core_dealercontactrole" ON ( "core_role"."id" =
"core_dealercontactrole"."role_id" ) WHERE "core_dealercontactrole"."id" =
8743 ORDER BY "core_role"."name" ASC'
}}}
Here are the models (with superfluous fields removed):
{{{
#!python
class Contact(models.Model):
first_name = models.CharField(blank=True, max_length=50)
last_name = models.CharField(blank=True, max_length=50)
class Meta:
ordering = ('last_name','first_name')
pass
class Dealer(models.Model):
contacts = models.ManyToManyField('Contact',
through='DealerContact', related_name='dealers')
name = models.CharField(db_index=True, max_length=250)
pass
class DealerContact(models.Model):
dealer = models.ForeignKey('Dealer',
related_name='dealercontacts+', on_delete=models.CASCADE)
contact = models.ForeignKey('Contact', related_name='+',
on_delete=models.CASCADE)
roles = models.ManyToManyField('Role',
through='DealerContactRole', related_name='+')
class Meta:
unique_together = ('dealer','contact')
pass
class DealerContactRole(models.Model):
dealercontact = models.ForeignKey('DealerContact',
related_name='+', on_delete=models.CASCADE)
role = models.ForeignKey('Role', related_name='+')
class Meta:
unique_together = ('dealercontact','role')
pass
class Role(models.Model):
name = models.CharField(db_index=True, max_length=100)
class Meta:
ordering = ('name',)
pass
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/25486>
Django <https://code.djangoproject.com/>
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