IPS

public void updateCuotaTotal() throws SQLException{

		Connection con = crearConexion();

		Statement stat = con.createStatement();
		ResultSet rs = stat.executeQuery("select dni, mes, sum(cantidad) as cant from pagos group by dni, mes");

		while(rs.next()){

			String dni = rs.getString("dni");
			String mes = rs.getString("mes");
			float cantidad = rs.getFloat("cant");


			PreparedStatement ps = con.prepareStatement("INSERT INTO cuota VALUES (?, ?, ?)");



			ps.setString(1, dni);
			ps.setString(2, mes);
			ps.setFloat(3, cantidad);
			ps.execute();
		}
		con.close();
	}