public Boolean ValidarLogin(ref Clases._USUARIOS USU)
        {
            Clases.ConectarDB dbSQLConn = new Clases.ConectarDB();
            dbSQLConn.ConecDb_Abrir();
            NpgsqlDataReader Dr = null;
            NpgsqlCommand    cmd;
            string           Sql;

            Sql = "SELECT idusu, nomusu, coddpt, stausu FROM usuarios WHERE usuusu = @usuusu AND clausu = @clausu";
            cmd = new NpgsqlCommand(Sql, dbSQLConn.Cnn);
            cmd.Parameters.AddWithValue("@usuusu", USU.usuusu);
            //cmd.Parameters.AddWithValue("@clausu", USU.clausu);
            cmd.Parameters.AddWithValue("@clausu", Util.GetMd5Hash(USU.clausu));
            Dr = cmd.ExecuteReader();
            if (Dr.HasRows)
            {
                Dr.Read();
                USU.idusu  = Dr.GetInt32(0);
                USU.nomusu = Dr.GetString(1);
                USU.coddpt = Dr.GetInt32(2);
                USU.stausu = Dr.GetInt32(3);
                Dr.Close();
                dbSQLConn.ConecDb_Close();
                return(true);
            }
            else
            {
                Dr.Close();
                dbSQLConn.ConecDb_Close();
                return(false);
            }
        }
        public static _PRODUCTOS[] getAll(string where = "", string order = "codpro")
        {
            List <_PRODUCTOS> producto  = new List <_PRODUCTOS>();
            ConectarDB        dbSQLConn = new Clases.ConectarDB();

            dbSQLConn.ConecDb_Abrir();
            NpgsqlDataReader Dr     = null;
            string           strSQL = $"SELECT codpro,despro,undunm,codgru,tiptiv,prepro,stapro FROM productos {(where!=""?$"WHERE {where}":"")}{(where != "" ? $"WHERE {where}" : "")} {(order != "" ? $"ORDER BY {order}" : "")}";
            NpgsqlCommand    cmd    = new NpgsqlCommand(strSQL, dbSQLConn.Cnn);

            Dr = cmd.ExecuteReader();
            if (Dr.HasRows)
            {
                while (Dr.Read())
                {
                    producto.Add(new _PRODUCTOS(Dr.GetInt32(0), Dr.GetString(1), Dr.GetString(2), Dr.GetInt32(3), Dr.GetString(4), Dr.GetDecimal(5), Dr.GetInt32(6)));
                }
            }
            return(producto.ToArray());
        }