public bool AdaugareOperaArta(OperaArta operaArta)
        {
            try
            {
                XElement xElement = XElement.Load(@numeFisier);

                if (operaArta is Tablou)
                {
                    Tablou tablou = (Tablou)operaArta;

                    xElement.Add(new XElement("operaArta",
                                              new XElement("tipOpera", "tablou"),
                                              new XElement("titlu", tablou.GetTitlu()),
                                              new XElement("numeArtist", tablou.GetNumeArtist()),
                                              new XElement("anRealizare", tablou.GetAnRealizare().ToString()),
                                              new XElement("genPictura", tablou.GetGenPictura()),
                                              new XElement("tehnica", tablou.GetTehnica())
                                              ));
                }
                else if (operaArta is Sculptura)
                {
                    Sculptura sculptura = (Sculptura)operaArta;

                    xElement.Add(new XElement("operaArta",
                                              new XElement("tipOpera", "sculptura"),
                                              new XElement("titlu", sculptura.GetTitlu()),
                                              new XElement("numeArtist", sculptura.GetNumeArtist()),
                                              new XElement("anRealizare", sculptura.GetAnRealizare().ToString()),
                                              new XElement("tip", sculptura.GetTip())
                                              ));
                }
                else
                {
                    xElement.Add(new XElement("operaArta",
                                              new XElement("tipOpera", "operaDeArta"),
                                              new XElement("titlu", operaArta.GetTitlu()),
                                              new XElement("numeArtist", operaArta.GetNumeArtist()),
                                              new XElement("anRealizare", operaArta.GetAnRealizare().ToString())
                                              ));
                }

                xElement.Save(@numeFisier);
                return(true);
            }
            catch (Exception)
            {
                return(false);
            }
        }
        private SqlCommand getUpdateSqlCommand(string titlu, OperaArta operaArta)
        {
            SqlCommand query = null;

            if (operaArta is Tablou)
            {
                Tablou tablou = (Tablou)operaArta;
                query = new SqlCommand("update OperaArta set [Titlu Opera]='" + tablou.GetTitlu() + "', [Nume Artist] ='" + tablou.GetNumeArtist() + "', [An Realizare] = '" + tablou.GetAnRealizare() + "', [Gen Pictura] ='" + tablou.GetGenPictura() + "', [Tehnica Pictura] ='" + tablou.GetTehnica() + "' where [Titlu Opera] ='" + titlu + "'", connection);
            }
            else if (operaArta is Sculptura)
            {
                Sculptura sculptura = (Sculptura)operaArta;
                query = new SqlCommand("update OperaArta set [Titlu Opera]='" + sculptura.GetTitlu() + "', [Nume Artist] ='" + sculptura.GetNumeArtist() + "', [An Realizare] = '" + sculptura.GetAnRealizare() + "', [Tip Sculptura] ='" + sculptura.GetTip() + "' where [Titlu Opera] ='" + titlu + "'", connection);
            }
            else if (operaArta is OperaArta)
            {
                query = new SqlCommand("update OperaArta set [Titlu Opera]='" + operaArta.GetTitlu() + "', [Nume Artist] ='" + operaArta.GetNumeArtist() + "', [An Realizare] = '" + operaArta.GetAnRealizare() + "' where [Titlu Opera] ='" + titlu + "'", connection);
            }

            return(query);
        }
        private SqlCommand getInsertSqlCommand(OperaArta operaArta)
        {
            SqlCommand query = null;

            if (operaArta is Tablou)
            {
                Tablou tablou = (Tablou)operaArta;
                query = new SqlCommand("insert into OperaArta values('Tablou','" + tablou.GetTitlu() + "','" + tablou.GetNumeArtist() + "','" + tablou.GetAnRealizare() + "','" + tablou.GetGenPictura() + "','" + tablou.GetTehnica() + "','')", connection);
            }
            else if (operaArta is Sculptura)
            {
                Sculptura sculptura = (Sculptura)operaArta;
                query = new SqlCommand("insert into OperaArta values('Sculptura','" + sculptura.GetTitlu() + "','" + sculptura.GetNumeArtist() + "','" + sculptura.GetAnRealizare() + "','','','" + sculptura.GetTip() + "')", connection);
            }
            else if (operaArta is OperaArta)
            {
                query = new SqlCommand("insert into OperaArta values('Opera de Arta','" + operaArta.GetTitlu() + "','" + operaArta.GetNumeArtist() + "','" + operaArta.GetAnRealizare() + "','','','')", connection);
            }


            return(query);
        }