public static void changeName(int LånerID, String newName) throws SQLIntegrityConstraintViolationException {
        String query = "UPDATE lånertabel SET Navn='"+newName+"' WHERE LånerID="+LånerID+";";
        try {
            Connection con = DBConnector.getConnection();
            PreparedStatement ps = con.prepareStatement(query);
            ps.executeUpdate();
            System.out.println("Navn ændret");
        } catch (SQLException ex) {
            System.out.println("Fejl i connection til Database");
            ex.printStackTrace();
        }
    }