Example code for using ODP.NET to connect to an Oracle database.

program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data;
using Oracle.DataAccess.Client;

namespace CSharp_Console
{
    static class Program
    {
        static void Main(string[] args)
        {
            // Properties.Settings.Default.OracleString contains the connection string, including credentials.
            // This is not good practice, but for this example I'm making an exception.
            using (var dbConnection = new OracleConnection(Properties.Settings.Default.OracleString))
            {
                try
                {
                    dbConnection.Open();

                    if (dbConnection.State == ConnectionState.Open)
                    {
                        Console.WriteLine("Connected to " + dbConnection.HostName + " running Oracle " + dbConnection.ServerVersion);
                    }
                }
                catch (Exception ex)
                {
                    Console.WriteLine("Something went wrong: " + ex.Message);
                }
                finally
                {
                    dbConnection.Close();
                }
            }
            
            Console.WriteLine("Press enter to continue...");
            Console.ReadLine();
        }
    }
}