ODP.NET数据库连接操作

using System;
using System.Data;
using Oracle.DataAccess.Client;
class Example
{
    OracleConnection con;
    void Connect()
    {
        con = new OracleConnection();
        con.ConnectionString = "User Id=USERID;Password=PAW;Data Source=ORCL;";
        con.Open();
        Console.WriteLine("Connected to Oracle");
        Console.WriteLine(con.ServerVersion);
    }
    void Close()
    {
        con.Close();
        con.Dispose();
    }
    void Reader()
    {
        //string strSQL = "select ename from emp";
        string strSQL = "select /* コメント */ ename from emp";
        OracleCommand myCmd = new OracleCommand(strSQL, con);
        OracleDataReader myReader = myCmd.ExecuteReader();
        Console.WriteLine("Read from OracleDataReader:");
        while(myReader.Read())
        {
            Console.WriteLine(myReader.GetString(0));
        }
        myReader.Close();
        myReader.Dispose();
    }
    //はじめての ODP.NET アプリケーション開発
    void ReadDataSet()
    {
        string strSQL = "select ename,empno from emp";
        OracleCommand myCmd = new OracleCommand(strSQL, con);
        OracleDataAdapter myDa = new OracleDataAdapter(myCmd);
        Console.WriteLine("Read from DataSet:");
        DataSet myDs = new DataSet();
        myDa.Fill(myDs, "emp");
        /* ---本文のソース---
        foreach(DataRow dr in myDs.Tables[0].Rows)
        {
            Console.WriteLine(dr[0]);
        }
        */
        /* ----全列の値を取得して整形して表示---*/
        foreach (DataRow dr in myDs.Tables[0].Rows)
        {
            for (int i = 0; i<myDs.Tables[0].Columns.Count; i++)
            {
                Console.Write("{0,10}", dr[i]);
            }
            Console.Write("\n");
         }
    }
    void delData()
    {
        string strSQL = "delete from emp where empno=9999";
        OracleCommand myCmd = new OracleCommand(strSQL, con);
        int res = myCmd.ExecuteNonQuery();
        if (res >= 1)
        Console.WriteLine("Delete Success");
        else
        Console.WriteLine("No Data to Delete");
    }
    void insData()
    {
        //string strSQL = "Insert into emp(empno,ename,deptno) values(9999,'ODP.NET',10)";
        string strSQL = "insert into test values ('あ')";
        OracleCommand myCmd = new OracleCommand(strSQL, con);
        OracleTransaction txn = con.BeginTransaction();
        try
        {
            int res = myCmd.ExecuteNonQuery();
            if (res == 1)
            {
                txn.Commit();
                Console.WriteLine("Insert Success and Commited.");
            }
        }
        catch(Exception e)
        {
            txn.Rollback();
            Console.WriteLine("No record was inserted ." + e.Message);
        }
    }
    static void Main()
    {       
        try
        {
            Console.WriteLine("Start:");
            while (true )
            {
                Example example = new Example();
                example.Connect();
                example.Reader();
                example.insData();
                example.delData();
                example.ReadDataSet();
                example.Close();
                Console.Write("\n");
                Console.WriteLine("End!!!!");
                if (Console.ReadKey(true).Key == ConsoleKey.Escape)
                    break;
            }
          
        }
        catch (Exception ex)
        {
           
            Console.WriteLine(ex.Message);
            //Console.WriteLine(ex.Message .StartsWith ("ORA"));
            Console.WriteLine("End!!!!"); 
            if (Console.ReadKey(true).Key == ConsoleKey.Escape)
            Console.WriteLine("Wait!!!!"); 
        }
    }
}