Comment 7 for bug 2028003

Reviewed: https://review.opendev.org/c/openstack/neutron/+/896522
Committed: https://opendev.org/openstack/neutron/commit/a4efc2dd80f1628e794e761d2d3e9e6c27e992b5
Submitter: "Zuul (22348)"
Branch: stable/yoga

commit a4efc2dd80f1628e794e761d2d3e9e6c27e992b5
Author: Rodolfo Alonso Hernandez <email address hidden>
Date: Tue Jul 18 02:38:47 2023 +0000

    [PostgreSQL] Subnet entity with ServiceType grouped by both tables

    The SQL clause "GROUP BY" in PostgreSQL requires the presence of all
    fields provided in the "SELECT" clause; this is not happening in
    MariaDB not MySQL.

    Since [1] (and the related patch [2] that are part of the same bug
    fix), when a resource with RBAC registers is selected, the "GROUP BY"
    clause is added to reduce the number of returned registers. The
    filed used is "id", present in all the RBAC controlled resources
    ('network', 'qospolicy', 'securitygroup', 'addressscope',
    'subnetpool', 'addressgroup'). That is in opposition to what was
    stated in the first paragraph "requires the presence of all
    fields provided in the "SELECT" clause". However it is possible
    to group only by a primary key [3].

    In [4] a prior change was introduced that modifies the "Subnet" entity
    to include a child table "SubnetServiceType". That introduces two new
    fields ("SubnetServiceType" fields) that are not present in the
    "GROUP BY" clause, causing the reported error in the LP bug.

    This patch is adding these two fields (that form the composite primary
    key of "SubnetServiceType" table) to the "GROUP BY" clause, when
    needed; if the query is executed by an administrator, the RBAC query
    won't be performed (an administrator has always permissions) and the
    "GROUP BY" clause won't be issued.

    [1]https://review.opendev.org/c/openstack/neutron-lib/+/884878
    [2]https://review.opendev.org/c/openstack/neutron/+/884877
    [3]https://learnsql.com/blog/must-appear-in-group-by-clause/
    [4]https://review.opendev.org/c/openstack/neutron/+/744512

    Closes-Bug: #2028003
    Change-Id: I18e65d79e56fe5995076eb9166da23fc14c92fc5
    (cherry picked from commit c831771053c29521f7e6e3a17997201f695925ec)
    (cherry picked from commit 96267a25821f1fa2117bbc364012da7d1de8bf0a)
    Conflicts:
            neutron/objects/subnet.py