NotGoogleKeep.txt

            DataTable rs = new DataTable();

            using (var odConnection = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=c:\Users\IIG\Desktop\test.xlsx;Extended Properties='Excel 12.0;HDR=YES;IMEX=1;';"))
            {
                odConnection.Open();

                using (OleDbCommand cmd = new OleDbCommand())
                {
                    cmd.Connection = odConnection;
                    cmd.CommandType = CommandType.Text;
                    cmd.CommandText = "SELECT * FROM [Sheet2$]";
                    using (OleDbDataAdapter oleda = new OleDbDataAdapter(cmd))
                    {
                        oleda.Fill(rs);
                    }
                }
                odConnection.Close();
            }
            foreach(DataRow row in rs.Rows)
            {
                foreach(object item in row.ItemArray)
                {
                    Console.Write(item +"\t");
                }
                Console.WriteLine();
            }
        }

public void Fillcombo()
{
string oradb = " Data Source=xe;User Id=dbname;Password=pws; ";
string query = "select id , name from table";
OracleConnection condatabase = new OracleConnection(oradb);
OracleCommand cmddatabase = new OracleCommand(query, condatabase);

        try
        {
            condatabase.Open();
            OracleDataReader myReader = cmddatabase.ExecuteReader(); ;
            myReader = cmddatabase.ExecuteReader();
            while (myReader.Read())
            {
                string sname = myReader.GetInt32(0).ToString();
                comboBox1.Items.Add(sname.ToString());
            }

        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
    }