C#读取Mysql blob字段

开发环境：Windows XP Professional SP3、VS2008、Winform、MySQL5.0、MySQL.Data6.2.3.0 1、从硬盘上读取一图片，将其转化为流，然后存储到此BLOB字段中 view plaincopy to clipboardprint? private void button1_Click( object sender,EventArgse) { byte

开发环境：Windows XP Professional SP3、VS2008、Winform、MySQL5.0、MySQL.Data6.2.3.0

 

1、从硬盘上读取一图片，将其转化为流，然后存储到此BLOB字段中

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1. private void button1_Click(object sender, EventArgs e)  
2.       {  
3.           byte[] bytes = null;  
4.           bytes = File.ReadAllBytes(@"C:/Documents and Settings/user/My Documents/My Pictures/11.jpg");  
5.           using (MySql.Data.MySqlClient.MySqlConnection conn = new MySql.Data.MySqlClient.MySqlConnection())  
6.           {  
7.               conn.ConnectionString = ConfigurationManager.ConnectionStrings["test"].ConnectionString;  
8.               MySql.Data.MySqlClient.MySqlCommand cmd = new MySql.Data.MySqlClient.MySqlCommand();  
9.               cmd.CommandText = "insert into test(id,picture) values(@id,@picture)";  
10.               cmd.CommandType = CommandType.Text;  
11.               cmd.Parameters.Add("@id", MySql.Data.MySqlClient.MySqlDbType.Int32);  
12.               cmd.Parameters.Add("@picture", MySql.Data.MySqlClient.MySqlDbType.Blob);  
13.   
14.               cmd.Parameters[0].Value = 15;  
15.               cmd.Parameters[1].Value = bytes;  
16.               cmd.Connection = conn;  
17.               conn.Open();  
18.   
19.               int affectedrows = cmd.ExecuteNonQuery();  
20.   
21.               cmd.Dispose();  
22.               conn.Close();  
23.           }  
24.   
25.       }  

private void button1_Click(object sender, EventArgs e) { byte[] bytes = null; bytes = File.ReadAllBytes(@"C:/Documents and Settings/user/My Documents/My Pictures/11.jpg"); using (MySql.Data.MySqlClient.MySqlConnection conn = new MySql.Data.MySqlClient.MySqlConnection()) { conn.ConnectionString = ConfigurationManager.ConnectionStrings["test"].ConnectionString; MySql.Data.MySqlClient.MySqlCommand cmd = new MySql.Data.MySqlClient.MySqlCommand(); cmd.CommandText = "insert into test(id,picture) values(@id,@picture)"; cmd.CommandType = CommandType.Text; cmd.Parameters.Add("@id", MySql.Data.MySqlClient.MySqlDbType.Int32); cmd.Parameters.Add("@picture", MySql.Data.MySqlClient.MySqlDbType.Blob); cmd.Parameters[0].Value = 15; cmd.Parameters[1].Value = bytes; cmd.Connection = conn; conn.Open(); int affectedrows = cmd.ExecuteNonQuery(); cmd.Dispose(); conn.Close(); } }

 

2、读取此BLOB字段，将其转化为图片显示在Picturebox控件上

 

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1. private void button2_Click(object sender, EventArgs e)  
2.         {  
3.             using (MySql.Data.MySqlClient.MySqlConnection conn = new MySql.Data.MySqlClient.MySqlConnection())  
4.             {  
5.                 conn.ConnectionString = ConfigurationManager.ConnectionStrings["test"].ConnectionString;  
6.                 conn.Open();  
7.   
8.                 MySql.Data.MySqlClient.MySqlCommand cmd = new MySql.Data.MySqlClient.MySqlCommand();  
9.                 cmd.CommandType = CommandType.Text;  
10.                 cmd.CommandText = "select id,picture from test where id = 11";  
11.                 cmd.Connection = conn;  
12.   
13.                 System.Data.Common.DbDataReader reader = cmd.ExecuteReader();  
14.                 byte[] buffer = null;  
15.                 if (reader.HasRows)  
16.                 {  
17.                     reader.Read();  
18.                     long len = reader.GetBytes(1, 0, null, 0, 0);//1是picture   
19.                     buffer = new byte[len];  
20.                     len = reader.GetBytes(1, 0, buffer, 0, (int)len);  
21.   
22.                     System.IO.MemoryStream ms = new System.IO.MemoryStream(buffer);  
23.                     System.Drawing.Image iamge = System.Drawing.Image.FromStream(ms);  
24.                     pictureBox1.Image = iamge;  
25.                 }  
26.             }  
27.   
28.         }  

private void button2_Click(object sender, EventArgs e) { using (MySql.Data.MySqlClient.MySqlConnection conn = new MySql.Data.MySqlClient.MySqlConnection()) { conn.ConnectionString = ConfigurationManager.ConnectionStrings["test"].ConnectionString; conn.Open(); MySql.Data.MySqlClient.MySqlCommand cmd = new MySql.Data.MySqlClient.MySqlCommand(); cmd.CommandType = CommandType.Text; cmd.CommandText = "select id,picture from test where id = 11"; cmd.Connection = conn; System.Data.Common.DbDataReader reader = cmd.ExecuteReader(); byte[] buffer = null; if (reader.HasRows) { reader.Read(); long len = reader.GetBytes(1, 0, null, 0, 0);//1是picture buffer = new byte[len]; len = reader.GetBytes(1, 0, buffer, 0, (int)len); System.IO.MemoryStream ms = new System.IO.MemoryStream(buffer); System.Drawing.Image iamge = System.Drawing.Image.FromStream(ms); pictureBox1.Image = iamge; } } }

 

数据库相关文件配置在App.config中，如果不用配置文件，可以写成：

string remote = "Persist Security Info=False;database=lhwtouch;server=服务器IP;user id=用户名;pwd=密码";

然后conn.ConnectionString = remote;即可。

 

 

后记：

 

   之前在.net中用的mysql库是：MySQLDriverCS，但是一直没有搞定，而且用官方给的读取blob字段也失败。于是改用MySql.Data，注意Mysql.Data5.0版本不支持读取Blob字段，所以需要用较高版本，我用的是MySQL.Data6.2.3.0。

 

MySql.Data6.2.3.0下载地址：http://download.csdn.net/source/2968152

MySql.Data5.0.9.0下载地址：http://download.csdn.net/source/2968157

 

代码提供者：http://hi.csdn.net/Dobzhansky，在此深表感谢！

 

http://blog.csdn.net/config_man/article/details/6123191