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(, , null, , int.MaxValue))];
                 sdr.GetBytes(, , blob, , blob.Length);
                 sdr.Close();
                 conn.Close();
                 var  fs = new FileStream("c:\\abd.pdf", FileMode.Create, FileAccess.Write);
                 fs.Write(blob, , blob.Length);
                 fs.Close();

             }
             catch (System.Exception ex)
             {
                 conn = null;
                 throw ex;
             }
             finally
             {
                 if (conn != null && conn.State == System.Data.ConnectionState.Open)
                     conn.Close();
             }

         }
     }
 }