public void borrar( String id_material) throws SQLException{

        String query = "BEGIN pack_material.eliminar(?);END;";
System.out.println(id_material);
        conexion.abrirConexion();
        cst = conexion.getConexion().prepareCall(query);
        cst.setString(1,id_material );
        cst.execute();
        cst.close();
        conexion.cerrarConexion();

     }