file.lisp

(defun get-products ()
  (with-connection (db)
    (let ((products (retrieve-all
                     (select (:id :name :short-description :price)
                       (from :product)))))
      (loop for product in products
            do (let* ((product-id (getf product :id))
                      (product-features (retrieve-all
                                         (select (:feature :description)
                                           (from :product-features)
                                           (where (:= :product-id product-id))))))
                 (push product-features product)
                 (push :features product)))
      products)))