C#从数据库导出数据到CSV

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.OracleClient;
using System.Data;
using System.IO;

namespace TextCSV
{
    class Program
    {
        static void Main(string[] args)
        {
            //用provide 报错，去掉就好了，注意需要引用oracleclient
            string strCon = "Password=egdb;User ID=egdb;Data Source=egdb;Persist Security Info=True";

            OracleConnection con = new OracleConnection(strCon);
            con.Open();
            OracleCommand cmd = new OracleCommand();
            cmd.Connection = con;
            cmd.CommandText = "select * from menu_perm";
            cmd.CommandType = CommandType.Text;

            OracleDataAdapter ad = new OracleDataAdapter(cmd);
            DataSet ds = new DataSet();

            ad.Fill(ds);
            con.Close();


            using (StreamWriter streamWriter = new StreamWriter(@"d:1.csv", false, Encoding.Default))
            {

                if (ds.Tables[0].Rows.Count > 0)
                {

                    foreach (DataRow row in ds.Tables[0].Rows)
                    {
                        StringBuilder str = new StringBuilder();
                        foreach (DataColumn col in ds.Tables[0].Columns)
                        {
                            //插入“，”自动会分割成不同的行。
                            str.Append(row[col.Caption.ToString()].ToString()+",");
                        }

                        streamWriter.WriteLine(str.ToString());
                    }
                    
                    
                    
                }

                streamWriter.Flush();
                streamWriter.Close();
            }
                 
        }
    }
}