private void button1_Click(object sender, EventArgs e)
        {
            if (sqlConnection.State == ConnectionState.Closed)
            {
                sqlConnection.Open();
            }
         
            DataContext db = new DataContext(sqlConnection);  
            Table<Automobil> Automobils = db.GetTable<Automobil>();
         
            var query =
                from cust in Automobils
                where cust.idAutomobil == 5
                select cust;

            foreach (var cust in query)
            {
                listBox1.Text = Convert.ToString(cust.idAutomobil);
            }
            
            if (sqlConnection.State == ConnectionState.Open)
            {
                sqlConnection.Close();
            }            
        }