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
19465	Virtual Base Classes Not Implemented	steven_ganz	nobody	"This model involving the standard ""diamond"" multiple inheritance hierarchy:
{{{
from django.db import models

class A(models.Model):
    name = models.CharField(max_length=256)
    class Meta:
        abstract = True

class B(A):
    class Meta:
        abstract = True

class C(A):
    class Meta:
        abstract = True

class D(B, C):
    pass
}}}

generates the sql:
{{{
BEGIN;
CREATE TABLE `teamBuilderWebVersion_d` (
    `id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY,
    `name` varchar(256) NOT NULL,
    `name` varchar(256) NOT NULL
)
;
COMMIT;
}}}

which triggers the error:
{{{
django.db.utils.DatabaseError: (1060, ""Duplicate column name 'name'"")
}}}

So it seems that although python considers there to be only one instance of a base class inherited twice, django considers there to be two."	Bug	closed	Uncategorized	1.4	Normal	duplicate			Unreviewed	0	0	0	0	0	0