Child models overwrite data of Parent model

[truebrain@…]

Given the next set of models:

class Project(models.Model):
  name = models.IntegerField()

class Subversion_Project(Project):
  revision = models.IntegerField()

class Mercurial_Project(Project):
  revision = models.CharField(max_length=64)
# This model is not used below, but it shows the intention of my database design

And the code:

project = Project(name = 1)
project.save()
sproject = Subversion_Project(project_ptr = project)
sproject.save()

The latter command overwrites the content of 'project' with all empty fields. When you print project.name or sproject.project.name before the save() it still is fine. After the save() it updates the project with empty values.

My solution is:

sproject = Subversion_Project(project_ptr = project)
for f in project._meta.local_fields: setattr(sproject, f.name, getattr(project, f.name))

Which is, putting it mildly, silly. Is this a bug, or do I expect too much of the system?

[Karen Tracey]

It's a use case not currently supported by inheritance, already covered by #7623, I believe.