I have a model that is backed by a database view.
class OrgCode(models.Model):
org_code = models.CharField(db_column=u'code',max_length=15)
org_description = models.CharField(max_length=250)
org_level_num = models.IntegerField()
class Meta:
db_table = u'view_FSS_ORG_PROFILE'
I need to reference this in another model
class AssessmentLocation(models.Model):
name = models.CharField(max_length=150)
org = models.ForeignKey(OrgCode)
I can't run syncdb because foreign key constraints cannot be created referencing a view.
u"Foreign key 'FK__main_asse__org__1D114BD1'
references object 'view_FSS_ORG_PROFILE'
which is not a user table.", None, 0, -214
7217900), None)
Command:
CREATE TABLE [main_assessmentlocation] (
[id] int IDENTITY (1, 1) NOT NULL PRIMARY KEY,
[name] nvarchar(150) NOT NULL,
[org] int NOT NULL REFERENCES [view_FSS_ORG_PROFILE] ([id]),
)
The workaround is to take out the Meta:db_table pointing to the view and let sync db create the the OrgCode table, then put the Meta:db_table back in after syncdb.
Is there a way to prevent the creation of foreign key constraints for certain models or fields?
Update: I added a static method to the related model indicating it's a view
class OrgCode(models.Model):
org_code = models.CharField(max_length=15)
org_description = models.CharField(max_length=250)
@staticmethod
def is_backend_view():
return True
Then overrode DatabaseCreation.sql_for_inline_foreign_key_references in django_mssql creation.py:
def sql_for_inline_foreign_key_references(self, field, known_models, style):
try:
field.rel.to.is_backend_view()
return "", False
except:
return super(DatabaseCreation,self).sql_for_inline_foreign_key_references(field, known_models, style)
The generated sql from syncdb leaves out the constraint:
CREATE TABLE [main_assessmentlocation] (
[id] int IDENTITY (1, 1) NOT NULL PRIMARY KEY,
[name] nvarchar(150) NOT NULL,
[org] int, -- NO FK CONSTRAINT ANYMORE --
);
It does involve hacking django_mssql so I'm going to keep on trying, maybe hooking into the django.db.backends.signals.connection_created signal will work...