private void button9999_Click(object sender, EventArgs e)
    {
      const string connStr = "Data Source=apex2006sql;Initial Catalog=Leather;Integrated Security=True;";
      const string query = "Select * From Invoice Where InvNumber = @InvNumber";
      using (SqlConnection conn = new SqlConnection(connStr))
      {
        conn.Open();
        using (SqlCommand cmd = new SqlCommand(query, conn))
        {
          cmd.Parameters.Add(new SqlParameter("@InvNumber", 1100));
          using (SqlDataReader dr = cmd.ExecuteReader())
          {
            using (DataTable dt = new DataTable())
            {
              dt.Load(dr);
              for (int i1 = 0; i1 < dt.Rows.Count; i1++)
              {
                DataRow row = dt.Rows[i1];
                string custName = Convert.ToString(row["CustName"]);
                string email = Convert.ToString(row["Email"]);
              }
            }
          }
        }
        conn.Close();
      }
    }

public void ReadMyData(string myConnString)
{
 string mySelectQuery = "SELECT DeptNo, DName FROM Dept";
 SQLiteConnection sqConnection = new SQLiteConnection(myConnString);
 SQLiteCommand sqCommand = new SQLiteCommand(mySelectQuery,sqConnection);
 sqConnection.Open();
 try
 {
   SQLiteDataReader sqReader = sqCommand.ExecuteReader();
   while (sqReader.Read())
   {
     Console.WriteLine(sqReader.GetInt32(0) + ", " + sqReader.GetString(sqReader.GetOrdinal("DName")));
   }
   sqReader.Close();
 }
 finally
 {
   sqConnection.Close();
 }
}