db-api-review: no oslo code uses created_at/updated_at fields

[Mark McLoughlin]

See https://review.openstack.org/17471

It looks like these fields:

  class ModelBase(object):
      ...
      created_at = Column(DateTime, default=timeutils.utcnow)
      updated_at = Column(DateTime, onupdate=timeutils.utcnow)

aren't actually set by any code in Oslo. Does it make sense to move these to an optional base class? Does it make sense to add common code for updating them?

[Zhongyue Luo (zyluo)]

I'll take a shot at this.
It seems not all projects are using those fields and in fact some do not wish to update the updated_at field automatically.
In order to put oslo.db code in all projects I think created_at and updated_at should be in a DatetimeMixin (I'm not sure this is the perfect name) class.
Maybe there should be a DatetimeMixin and a OnUpdateDatetimeMixin?
What would be a good name for these mixins? suggestions?

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/26576

[Zhongyue Luo (zyluo)]

https://review.openstack.org/#/c/26576/

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/26576
Committed: http://github.com/openstack/oslo-incubator/commit/fa84da27458847d90075c9f8d77333b532d7882a
Submitter: Jenkins
Branch: master

commit fa84da27458847d90075c9f8d77333b532d7882a
Author: Zhongyue Luo <email address hidden>
Date: Wed Apr 10 10:31:03 2013 +0800

    Removes created_at, updated_at from ModelBase

    Created a 'TimestampMixin' class.
    Next step is to update Nova which is the only project using oslo.db

    Fixes bug #1119702

    Change-Id: I1ffcc09a2971e6e6102da7ecb855a2837a159baf