class AddUniqueIndexToLabels < ActiveRecord::Migration
include Gitlab::Database::MigrationHelpers
DOWNTIME = true
DOWNTIME_REASON = 'This migration removes duplicated labels.'
disable_ddl_transaction!
def up
select_all('SELECT title, project_id, COUNT(id) as cnt FROM labels GROUP BY project_id, title HAVING COUNT(id) > 1').each do |label|
label_title = quote_string(label['title'])
duplicated_ids = select_all("SELECT id FROM labels WHERE project_id = #{label['project_id']} AND title = '#{label_title}' ORDER BY id ASC").map{ |label| label['id'] }
label_id = duplicated_ids.first
duplicated_ids.delete(label_id)
execute("UPDATE label_links SET label_id = #{label_id} WHERE label_id IN(#{duplicated_ids.join(",")})")
execute("DELETE FROM labels WHERE id IN(#{duplicated_ids.join(",")})")
end
remove_index :labels, column: :project_id if index_exists?(:labels, :project_id)
remove_index :labels, column: :title if index_exists?(:labels, :title)
add_concurrent_index :labels, [:group_id, :project_id, :title], unique: true
end
def down
remove_index :labels, column: [:group_id, :project_id, :title] if index_exists?(:labels, [:group_id, :project_id, :title], unique: true)
add_concurrent_index :labels, :project_id
add_concurrent_index :labels, :title
end
end