using Oracle.DataAccess.Client;

        /// <summary>
        /// Создаёт объект соединения с БД Oracle
        /// </summary>
        /// <param name="listener">Сервис связи</param>
        /// <param name="login">Логин в БД</param>
        /// <param name="password">Пароль для заданного логина</param>
        /// <param name="host">Сервер БД</param>
        /// <param name="port">Порт сервера для доступа к БД</param>
        public OracleConnection(string listener, string login, string password, string host, string port)
        {
            m_authorizationString = login + "/" + password + "@" + listener;
            //m_connection = new Oracle.DataAccess.Client.OracleConnection("User Id=" + login + ";Password=" + password + "; Data Source=" + listener + ";" );
            m_connection = new Oracle.DataAccess.Client.OracleConnection("Data Source=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)" +
                "(HOST=" + host + ")(PORT=" + port + ")))" + "(CONNECT_DATA=(SERVER=DEDICATED)(SID=" + listener + ")));" +
                "User Id=" + login + ";Password=" + password + ";");
            //Log.AppLog.LogString("Connecting to DB with credentials " + m_authorizationString);
            try
            {
                m_connection.Open();
            }
            catch (Oracle.DataAccess.Client.OracleException e)
            {
                Log.AppLog.LogString("Connection failed - " + e.Message);
                //Console.WriteLine(e.Message);
            }
        }

        /// <summary>
        /// Выполнить одиночный запрос
        /// </summary>
        /// <param name="query">Строка SQL-запроса</param>
        /// <returns>Признак успешного выполнения</returns>
        public bool PerformQuery(string query)
        {
            try
            {
                if (query.Length > 4000) return false;
                OracleCommand command = m_connection.CreateCommand();
                command.CommandText = query;
                command.ExecuteScalar();
                command.Dispose();
                return true;
            }
            catch (System.Exception ex)
            {
                Log.AppLog.LogString("Error in query: \"" + ex.Message + "\" - with query " + query);
                return false;
            }
        }

        /// <summary>
        /// Чтение данных из таблицы
        /// </summary>
        /// <param name="query">Запрос</param>
        /// <param name="fields">Поля в результате запроса</param>
        /// <returns>Список наборов значений полей</returns>
        public List<string[]> QueryData(string query, params string[] fields) {
            OracleCommand command = m_connection.CreateCommand();
            command.CommandText = query;

            OracleDataReader reader = command.ExecuteReader();
            List<string[]> ret = new List<string[]>();
            while (reader.Read()) {
                string[] read = new string[fields.Length];
                for (int i = 0; i < fields.Length; ++i) read[i] = reader[fields[i]].ToString();
                ret.Add(read);
            }
            return ret;
        }

OracleConnection conn = new OracleConnection("testbase", "scott", "tiger", "192.168.1.5", "1521");
List<string[]> names = conn.QueryData("SELECT NAME, DATE FROM MYTABLE WHERE ID>150", "NAME", "DATE");
foreach(string[] record in names){
  Console.WriteLine("Name is " + record[0]);
}

class Person{
  public string Name {get; private set;}
  public string Date {get; private set;}
  public string Comment {get; private set;}

  public Person(string name, string date, string comment){Name = name; Date = date; Comment = comment;}
}
//...
OracleConnection conn = new OracleConnection("testbase", "scott", "tiger", "192.168.1.5", "1521");
List<string[]> names = conn.QueryData("SELECT NAME, DATE FROM MYTABLE WHERE ID>150", "NAME", "DATE");
IEnumerable<Person> persons = names.Select(record => new Person(record[0], record[1], "none"));
dataGridViewPeople.DataSource = persons;