BEGIN; ALTER TABLE users ADD COLUMN role "UserRoleMapping" DEFAULT 'user' NOT NULL; ALTER TABLE users ADD COLUMN project_id int; UPDATE users SET project_id = user_projects.project_id, role = user_projects.role FROM user_projects INNER JOIN user_projects ON user_projects.user_id = users.id; DROP TABLE user_projects; ALTER TABLE users ALTER COLUMN project_id ADD CONSTRAINT users_project_id_fkey FOREIGN KEY (project_id) REFERENCES projects (id) MATCH FULL; COMMIT;