Close OracleConnection after ExecuteReader

Question

This is my current pattern

private void ReadData(string connString, string cmdString)
{
    using (OracleConnection conn = new OracleConnection(connString))
    {
        conn.Open();
        OracleCommand cmd = new OracleCommand(cmdString, conn);
        OracleDataReader reader = cmd.ExecuteReader();
        //some long operation using reader
    }
}

In the above case, the connection remains open while the long operation is going on. Is there a way I could close the connection but still preserve the reader. Is that going to be advantageous?

Answer 1

If by long operations you mean to say that you need to do extra operations on the database (like update/insert/delete), then you cannot close the connection.

If you want to read the data and do some calculation based on it, then you should modify you pattern to: 1. read all the data, 2. close the connection, 3. do long operation on the data.

using System;
using System.Collections.Generic;
using Oracle.DataAccess.Client;

namespace Utils
{
    class Test
    {
        private class Class
        {
            public string FirstProperty { get; set; }
            public string SecondProperty { get; set; }
        }

        private void ReadData(string connString, string cmdString)
        {
            List<Class> data = new List<Class>();
            using (OracleConnection conn = new OracleConnection() { ConnectionString = connString })
            using (OracleCommand objCmd = new OracleCommand()
            {
                Connection = conn,
                CommandText = cmdString
            })
            {
                try
                {
                    conn.Open();
                }
                catch (OracleException)
                {
                    OracleConnection.ClearPool(conn);
                    conn.Open();
                }
                using (OracleDataReader dataReader = objCmd.ExecuteReader())
                {
                    while (dataReader.Read())
                        data.Add(new Class()
                        {
                            FirstProperty = dataReader.GetString(0),
                            SecondProperty = dataReader.GetString(1)
                        });
                }
                conn.Close();
            }
            //some long operation using data
        }
    }
}