room.java

    @Query("SELECT id, title, description, dateCreated, certificateLink, deliveryStatus, userId\n" +
           "FROM Certificates\n" +
           "WHERE userId = :userId\n" +
           "ORDER BY expirationDate")
    List<CertificateDto> getAllNotifications(long userId);

    @Query("SELECT id, title, description, dateCreated, certificateLink, deliveryStatus, userId\n" +
           "FROM Certificates\n" +
           "WHERE userId = :userId AND\n" +
           "      expirationDate <= date('now', '+8 hour') AND -- TODO: get client timezone from header\n" +
           "      deliveryStatus = 0\n" +
           "ORDER BY expirationDate")
    List<CertificateDto> getPendingNotifications(long userId);