From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Thu, 3 Dec 2015 19:21:13 +0000 (-0500)
Subject: Run NOT NULL alterations before foreign key adds
X-Git-Url: https://review.fuel-infra.org/gitweb?a=commitdiff_plain;h=0f58db9d645383db48e402f69d733b2013a6748e;p=openstack-build%2Fneutron-build.git

Run NOT NULL alterations before foreign key adds

The "migrate resources table" migration will fail
for some MariaDB versions if the NOT NULL alteration
is applied after the foreign key constraint has been
added [1].   This patch reverses the order so that
NOT NULL is applied first.

[1] http://paste.openstack.org/show/480820/

Change-Id: Iab2b9fc7d82c739ae458ee48c1830541fb0f9579
---

diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/contract/8a6d8bdae39_migrate_neutron_resources_table.py b/neutron/db/migration/alembic_migrations/versions/mitaka/contract/8a6d8bdae39_migrate_neutron_resources_table.py
index b2a424ce0..e7acce8ba 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/contract/8a6d8bdae39_migrate_neutron_resources_table.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/contract/8a6d8bdae39_migrate_neutron_resources_table.py
@@ -49,15 +49,18 @@ standardattrs = sa.Table(
 def upgrade():
     generate_records_for_existing()
     for table, model in TABLE_MODELS:
-        # add the constraint now that everything is populated on that table
+        # add constraint(s) now that everything is populated on that table.
+        # note that some MariaDB versions will *not* allow the ALTER to
+        # NOT NULL on a column that has an FK constraint, so we set NOT NULL
+        # first, then the FK constraint.
+        op.alter_column(table, 'standard_attr_id', nullable=False,
+                        existing_type=sa.BigInteger(), existing_nullable=True,
+                        existing_server_default=False)
         op.create_foreign_key(
             constraint_name=None, source_table=table,
             referent_table='standardattributes',
             local_cols=['standard_attr_id'], remote_cols=['id'],
             ondelete='CASCADE')
-        op.alter_column(table, 'standard_attr_id', nullable=False,
-                        existing_type=sa.BigInteger(), existing_nullable=True,
-                        existing_server_default=False)
         op.create_unique_constraint(
             constraint_name='uniq_%s0standard_attr_id' % table,
             table_name=table, columns=['standard_attr_id'])