Requêtes select count

public partial class Window3 : Window
    {
        public Window3()
        {
            InitializeComponent();
        }
        SqlConnection sqlcon = new SqlConnection("Data Source=TGOCLC0H5YV0\\SQLSERVER;Initial Catalog=BDCsMac; Trusted_Connection=True;");
        private void valider_Click(object sender, RoutedEventArgs e)
        {
{
string myquery = "SELECT COUNT(1) FROM Demandes, Stock WHERE Demandes.Designation=Stock.Libelle AND Demandes.Qte<=Stock.Qte";
            SqlCommand mycmd = new SqlCommand(myquery, sqlcon);
            mycmd.CommandType = CommandType.Text;
            int count = Convert.ToInt32(mycmd.ExecuteScalar());
            if (count == 1)
            {
                    msg.Text = txtNom.Text + " du service " + txtService.Text + " a fait une demande de " + txtQte.Text + txtDesignation.Text + " existante dans le stock; le " + txtDate.Text;
                    sqlcon.Open();
                    string nreq = "insert into dbo.MsgDmd(MsgDmd) values(@MsgDmd)";
                    SqlCommand ncmd = new SqlCommand(nreq, sqlcon);
                    ncmd.CommandType = CommandType.Text;
                    ncmd.Parameters.Add(new SqlParameter("@MsgDmd", msg.Text));
                    ncmd.ExecuteNonQuery();
                    MessageBox.Show("Demande enregistrée...");
                    txtNom.Text = "";
                    txtService.Text = "";
                    txtQte.Text = "";
                    txtDesignation.Text = "";
                    txtDate.Text = "";
            }
            else
            {
                MessageBox.Show("Demande inexistante dans le stock...");
            }