Sequel.migration do up do SequelRails.connection.run(%{ ALTER TABLE shared_entities DROP CONSTRAINT shared_entities_pkey; }) SequelRails.connection.run(%{ ALTER TABLE shared_entities ADD COLUMN id uuid NOT NULL default uuid_generate_v4(); }) SequelRails.connection.run(%{ ALTER TABLE shared_entities ADD PRIMARY KEY (id); }) end down do SequelRails.connection.run(%{ ALTER TABLE shared_entities DROP CONSTRAINT shared_entities_pkey; }) SequelRails.connection.run(%{ ALTER TABLE shared_entities ADD PRIMARY KEY (recipient_id, entity_id); }) SequelRails.connection.run(%{ ALTER TABLE shared_entities DROP COLUMN id; }) end end