C# 连接 Oracle，读取Blob字段数据，存到文件中去，包括pdf等等

代码如下，记得引入Oracle的dll

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.OracleClient;
using System.Data.SqlClient;
using System.IO;

namespace WindowsFormsApplication3
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void simpleButton1_Click(object sender, EventArgs e)
        {
            var mServiceName = "20.";
            var mUserName = "k_";
            var  mPsw = "z!";
            string connstring = string.Format("Data Source={0};User Id={1};Password={2}", mServiceName, mUserName, mPsw);
            OracleConnection conn = new OracleConnection(connstring);
            var a = "SELECT DOC_NT FROM dd WHERE  DOT_ID='6ff157b3-a482-4731-935d-782af8ca60cd'";
            OracleCommand cmd = new OracleCommand(a, conn);
            try
            {
                conn.Open();
                OracleDataReader sdr = cmd.ExecuteReader();
                sdr.Read();
                var blob = new Byte[(sdr.GetBytes(0, 0, null, 0, int.MaxValue))];
                sdr.GetBytes(0, 0, blob, 0, blob.Length);
                sdr.Close();
                conn.Close();
                var  fs = new FileStream("c:\abd.pdf", FileMode.Create, FileAccess.Write);
                fs.Write(blob, 0, blob.Length);
                fs.Close();
              
            }
            catch (System.Exception ex)
            {
                conn = null;
                throw ex;
            }
            finally
            {
                if (conn != null && conn.State == System.Data.ConnectionState.Open)
                    conn.Close();
            }
       
        }
    }
}