{:up ["ALTER TABLE orders ADD recurrence VARCHAR(512)"
      "ALTER TABLE orders ADD end_date TIMESTAMPTZ"
      "CREATE TABLE recurrence_exceptions(
           order_id INT,
           order_date TIMESTAMPTZ NOT NULL,
           status order_state DEFAULT 'waiting',
           PRIMARY KEY(order_id, order_date),
           CONSTRAINT fk_customer FOREIGN KEY(order_id) REFERENCES orders(id) ON DELETE CASCADE)"
      "UPDATE orders SET end_date = o.order_date
         FROM orders AS o
         WHERE orders.id = o.id"]
 :down ["DROP TABLE recurrence_exceptions"
        "ALTER TABLE orders DROP COLUMN end_date"
        "ALTER TABLE orders DROP COLUMN recurrence"]}