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
5669	ForeignKey (sometimes) not created in a database, constraint missing	dwich	nobody	"Hi,
I have this piece of code. Save it as a model definition in a testing django project.

{{{
from django.db import models
from django.contrib.auth.models import User

class Region(models.Model):
	name = models.CharField(maxlength=128)

class ServiceCategory(models.Model):
	name = models.CharField(maxlength=128)

class Service(models.Model):
	category = models.ManyToManyField(ServiceCategory)
	name = models.CharField(maxlength=128)

class ServiceVariant(models.Model):
	service = models.ForeignKey(Service)
	region = models.ForeignKey(Region)
	name = models.CharField(maxlength=128)

class CustomerProfile(models.Model):
	user = models.ForeignKey(User, unique=True)
	name = models.CharField(maxlength=64)

class BugTest(models.Model):
	name = models.CharField(maxlength=64)
}}}

Then create the database or simply display the SQL using `manage.py sqlall myapp` and save it. Then comment the last class - !BugTest. Recreate the database or show the SQL again and save it. If you diff it, there are two differencies:

 1. There's no table `bugtest` in the second SQL dump because there was no definition for it. Which is correct.
 2. The second difference is probably a bug - there's no constraint for !ServiceVariant class refering to Service. The `ALTER TABLE myapp_servicevariant ADD CONSTRAINT ...` is missing.

I use (freshly exported) django SVN version (and MySQL 5.0.x)."		closed	Database layer (models, ORM)	dev		duplicate	foreign key, constraint, model, database		Unreviewed	0	0	0	0	0	0