使用OleDbCommand对象更新SQL Server中的二进制文件
| 作者 朱二 |
| 利用ADO.NET中的OleDbConnection\OleDbCommand 可以方便的对SQL Server中的二进制文件进行更新操作，下面是详细的代码演示演示环境：数据库机器名 ：s_test登陆名 ：sa密码 ：7890数据库名 db_test下面建立一个表： |
| create table tb_test(id int identity(1,1),photo image ,constraint pk_tb_test primary key(id)) |
| 一、将硬盘上的文件保存至数据库(C#) |
| //----------------------------------------------------------//----------------------------------------------------------//下面的示例将c:\1.txt文件保存至数据库的tb_test表中//----------------------------------------------------------//----------------------------------------------------------using System;using System.IO;?using System.Data;using System.Data.OleDb;class image_test{[STAThread]static void Main(string[] args){try{//初始化OleDbConnection和OleDbCommandOleDbConnection cn = new OleDbConnection("provider=sqloledb;server=s_test;user id=sa;password=7890;initial catalog=db_test");OleDbCommand cmd = new OleDbCommand("INSERT tb_test(photo) VALUES(?)",cn);//打开文件FileStream fs = new FileStream("c:\\1.txt", FileMode.Open, FileAccess.Read);Byte[] b = new Byte[fs.Length];fs.Read(b, 0, b.Length);fs.Close();//打开连接OleDbParameter prm = new OleDbParameter("@photo",OleDbType.VarBinary ,b.Length,?ParameterDirection.Input, false, 0, 0, null,DataRowVersion.Current, b);cmd.Parameters.Add(prm);cn.Open();//执行if (cmd.ExecuteNonQuery() == 1)Console.WriteLine("OK");elseConsole.WriteLine("Fail");?cn.Close();}catch(Exception ex){Console.WriteLine(ex.Message );}}}? |
| 三、更新数据库中保存的文件 |
| //----------------------------------------------------------//----------------------------------------------------------//下面的示例用将数据库的tb_test表中ID=1的记录的photo更新为c:\1.txt//----------------------------------------------------------//----------------------------------------------------------using System;using System.IO;?using System.Data;using System.Data.OleDb;class image_test{[STAThread]static void Main(string[] args){try{//初始化OleDbConnection和OleDbCommandOleDbConnection cn = new OleDbConnection("provider=sqloledb;server=s_test;user id=sa;password=7890;initial catalog=db_test");OleDbCommand cmd = new OleDbCommand("UPDATE tb_test SET photo= ? WHERE ID=1",cn);//打开文件FileStream fs = new FileStream("c:\\1.txt", FileMode.Open, FileAccess.Read);Byte[] b = new Byte[fs.Length];fs.Read(b, 0, b.Length);fs.Close();//打开连接OleDbParameter prm = new OleDbParameter("@photo",OleDbType.VarBinary ,b.Length,?ParameterDirection.Input, false, 0, 0, null,DataRowVersion.Current, b);cmd.Parameters.Add(prm);cn.Open();//执行if (cmd.ExecuteNonQuery() == 1)Console.WriteLine("OK");elseConsole.WriteLine("Fail");?cn.Close();}catch(Exception ex){Console.WriteLine(ex.Message );}}} |
