/// <summary>
        /// get an instance of object
        /// </summary>
        /// <param name="myID"></param>
        public dh_herramientas getObject(System.Int32 myID)
        {
            dh_herramientas dh_herram = new dh_herramientas();
            CnxBase         myBase    = new CnxBase();
            string          reqSQL    = "SELECT id_herramienta,id_subcategoria,herramienta FROM dh_herramientas WHERE (id_herramienta=" + myID + ")";

            try
            {
                NpgsqlConnection myConn    = myBase.OpenConnection(myBase.cnxString);
                NpgsqlCommand    myCommand = new NpgsqlCommand(reqSQL, myConn);
                NpgsqlDataReader myReader  = myCommand.ExecuteReader();
                if (myReader.Read())
                {
                    dh_herram.id_herramienta  = Convert.ToInt32(myReader[0]);
                    dh_herram.id_subcategoria = Convert.ToInt32(myReader[1]);
                    dh_herram.herramienta     = myReader[2].ToString();
                }
                myBase.CloseConnection(myConn);
            }
            catch (Exception myErr)
            {
                throw (new Exception(myErr.ToString() + reqSQL));
            }
            return(dh_herram);
        }
        /// <summary>
        /// add a record
        /// </summary>
        /// <param name="myID"></param>
        public void Insert(dh_herramientas mydh_herram)
        {
            CnxBase myBase = new CnxBase();
            string  reqSQL = "INSERT INTO dh_herramientas (id_subcategoria, herramienta) VALUES (" + mydh_herram.id_subcategoria + ",'" + mydh_herram.herramienta + "')";

            try
            {
                NpgsqlConnection myConn    = myBase.OpenConnection(myBase.cnxString);
                NpgsqlCommand    myCommand = new NpgsqlCommand(reqSQL, myConn);
                myCommand.ExecuteNonQuery();
                myBase.CloseConnection(myConn);
            }
            catch (Exception myErr)
            {
                throw (new Exception(myErr.ToString() + reqSQL));
            }
        }
        /// <summary>
        /// modify a record
        /// </summary>
        public void Update(dh_herramientas mydh_herram)
        {
            CnxBase myBase = new CnxBase();
            string  reqSQL = "UPDATE dh_herramientas SET id_herramienta=" + mydh_herram.id_herramienta + ",id_subcategoria=" + mydh_herram.id_subcategoria + ",herramienta='" + mydh_herram.herramienta + "' WHERE (id_herramienta=" + mydh_herram.id_herramienta + ")";

            try
            {
                NpgsqlConnection myConn    = myBase.OpenConnection(myBase.cnxString);
                NpgsqlCommand    myCommand = new NpgsqlCommand(reqSQL, myConn);
                myCommand.ExecuteNonQuery();
                myBase.CloseConnection(myConn);
            }
            catch (Exception myErr)
            {
                throw (new Exception(myErr.ToString() + reqSQL));
            }
        }