CREATE TABLE IF NOT EXISTS member_classes (
  id              UUID DEFAULT uuid_generate_v4(),
  name            TEXT NOT NULL,
  show            BOOLEAN NOT NULL DEFAULT TRUE,
  parent_id       UUID,
  created_at      BIGINT NOT NULL DEFAULT (extract(epoch from now()) * 1000),
  updated_at      BIGINT NOT NULL DEFAULT (extract(epoch from now()) * 1000),
  PRIMARY KEY (id),
  UNIQUE (name)
);

-- trigger (updated_at)
CREATE TRIGGER tg_member_classes_updated_at
  BEFORE UPDATE
  ON member_classes
  FOR EACH ROW
  EXECUTE PROCEDURE update_updated_at_column();