gitlab-org--gitlab-foss/db/migrate/20170418103908_delete_orphan_notification_settings.rb
Jan Provaznik 0fc9f9d3e7 Add version 4.2 to all existing migrations
DB schema generated by a migration may look different in
rails 4 and 5 (because rails 5 may use different default values).
For this reason it's important to explicitly set for which rails
version a migration was written for.

See https://stackoverflow.com/questions/35929869/activerecordmigration-deprecation-warning-asks-for-rails-version-but-im-no/35930912#35930912
2018-11-22 13:18:28 +01:00

24 lines
841 B
Ruby

class DeleteOrphanNotificationSettings < ActiveRecord::Migration[4.2]
DOWNTIME = false
def up
execute("DELETE FROM notification_settings WHERE EXISTS (SELECT true FROM (#{orphan_notification_settings}) AS ns WHERE ns.id = notification_settings.id)")
end
def down
# This is a no-op method to make the migration reversible.
# If someone is trying to rollback for other reasons, we should not throw an Exception.
# raise ActiveRecord::IrreversibleMigration
end
def orphan_notification_settings
<<-SQL
SELECT notification_settings.id
FROM notification_settings
LEFT OUTER JOIN namespaces
ON namespaces.id = notification_settings.source_id
WHERE notification_settings.source_type = 'Namespace'
AND namespaces.id IS NULL
SQL
end
end