Sequel.migration do up do create_table :shared_entities do primary_key :id Uuid :user_id, null: false, :index => true Uuid :entity_id, null: false Text :type, null: false DateTime :created_at, default: Sequel::CURRENT_TIMESTAMP DateTime :updated_at, default: Sequel::CURRENT_TIMESTAMP end alter_table(:shared_entities) do add_index [:user_id, :entity_id], :unique => true end end down do drop_table :shared_entities end end