Comment 8 for bug 1798163

Reviewed: https://review.openstack.org/611315
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=6bd7e8a958f53e2288b41a27528a008e3cfb2802
Submitter: Zuul
Branch: stable/rocky

commit 6bd7e8a958f53e2288b41a27528a008e3cfb2802
Author: Mohammed Naser <email address hidden>
Date: Tue Oct 16 19:54:40 2018 +0200

    Use unique consumer_id when doing online data migration

    If there are multiple consumers having allocations to the same
    resource provider, with different classes, it will attempt
    multiple INSERTs with the same consumer_id which is not allowed
    because of the database constraints.

    This patch adds a simple GROUP BY in order to ensure that the
    database server only provides us with unique values to avoid
    trying to INSERT duplicate values.

    Conflicts:
          nova/tests/functional/api/openstack/placement/db/test_consumer.py

    NOTE(mriedem): The conflict is due to not having change
    I7f5f08691ca3f73073c66c29dddb996fb2c2b266 in Rocky.

    Change-Id: I1acba5e65cd562472f29e354c6077f82844fa87d
    Closes-Bug: #1798163
    (cherry picked from commit 730936e535e67127c76d4f27649a16d8cf05efc9)