开发环境:Windows XP Professional SP3、VS2008、Winform、MySQL5.0、MySQL.Data.dll 6.2.3.0
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
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();//此处可以不用调用, conn.Close();// 离开 using 块, connection 会自行关闭 }}
2、读取此BLOB字段,将其转化为图片显示在Picturebox控件上
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=数据库名;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.dll ,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.Data.dll 6.2.3.0。
MySql.Data.dll 6.2.3.0下载地址:
MySql.Data.dll 5.0.9.0下载地址:
代码提供者:,在此深表感谢!
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