/// <summary>
        /// get an instance of object
        /// </summary>
        /// <param name="myID"></param>
        public dh_herramientas_carros getObject(int id_herramienta_carro)
        {
            dh_herramientas_carros dh_herramcarro = new dh_herramientas_carros();
            CnxBase myBase = new CnxBase();
            string  reqSQL = "SELECT id_herramienta_carro, id_herramienta,id_carro,cantidad FROM dh_herramientas_carros WHERE (id_herramienta_carro=" + id_herramienta_carro + ")";

            try
            {
                NpgsqlConnection myConn    = myBase.OpenConnection(myBase.cnxString);
                NpgsqlCommand    myCommand = new NpgsqlCommand(reqSQL, myConn);
                NpgsqlDataReader myReader  = myCommand.ExecuteReader();
                if (myReader.Read())
                {
                    dh_herramcarro.id_herramienta_carro = Convert.ToInt32(myReader[0]);
                    dh_herramcarro.id_herramienta       = Convert.ToInt32(myReader[1]);
                    dh_herramcarro.id_carro             = Convert.ToInt32(myReader[2]);
                    dh_herramcarro.cantidad             = Convert.ToInt32(myReader[3]);
                }
                myBase.CloseConnection(myConn);
            }
            catch (Exception myErr)
            {
                throw (new Exception(myErr.ToString() + reqSQL));
            }
            return(dh_herramcarro);
        }
        /// <summary>
        /// add a record
        /// </summary>
        /// <param name="myID"></param>
        public void Insert(dh_herramientas_carros mydh_herramcarro)
        {
            CnxBase myBase = new CnxBase();
            string  reqSQL = "INSERT INTO dh_herramientas_carros (id_herramienta, id_carro, cantidad) VALUES (" + mydh_herramcarro.id_herramienta + "," + mydh_herramcarro.id_carro + "," + mydh_herramcarro.cantidad + ")";

            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_carros mydh_herramcarro)
        {
            CnxBase myBase = new CnxBase();
            string  reqSQL = "UPDATE dh_herramientas_carros SET id_carro=" + mydh_herramcarro.id_carro + ",cantidad=" + mydh_herramcarro.cantidad + " WHERE (id_herramienta_carro=" + mydh_herramcarro.id_herramienta_carro + ")";

            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));
            }
        }