canvas-lms/db/migrate/20120705144244_add_unique_i...

31 lines
1.2 KiB
Ruby

#
# Copyright (C) 2012 - present Instructure, Inc.
#
# This file is part of Canvas.
#
# Canvas is free software: you can redistribute it and/or modify it under
# the terms of the GNU Affero General Public License as published by the Free
# Software Foundation, version 3 of the License.
#
# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
# details.
#
# You should have received a copy of the GNU Affero General Public License along
# with this program. If not, see <http://www.gnu.org/licenses/>.
class AddUniqueIndexOnFavorites < ActiveRecord::Migration[4.2]
tag :postdeploy
def self.up
# cleanup must happen synchronously in order to create the unique index
Favorite.where("id NOT IN (SELECT * FROM (SELECT MIN(id) FROM #{Favorite.quoted_table_name} GROUP BY user_id, context_id, context_type) x)").delete_all
add_index :favorites, [:user_id, :context_id, :context_type], :unique => true, :name => "index_favorites_unique_user_object"
end
def self.down
remove_index :favorites, :name => "index_favorites_unique_user_object"
end
end