二进制图片存储问题

首先..定义一个函数..将图片转化为二进制码

//定义将图片转化为长二进制代码的函数getphoto()
         public Byte[] getphoto(string photopath)
         {
             string str = photopath;
             FileStream file = new FileStream(str, FileMode.Open, FileAccess.Read);
             Byte[] bytBLOBData = new Byte[file.Length];
             file.Read(bytBLOBData, 0, bytBLOBData.Length);
             file.Close();
             return bytBLOBData;
         }//这是定义函数..

然后..就是将转换成二进制码的图片插入数据库中..下面是简单的也是重要的sql语句..
if (this.pictureBox1.Image != null)
                     {
                         sql1 = sql1 + ",Photo";
                         sql2 = sql2 + ",bytBLOBData";
                         Byte[] bytBLOBData = getphoto(openFileDialog1.FileName);
                         cmd.Parameters.Add(new OleDbParameter("jpeg", OleDbType.Binary, bytBLOBData.Length, ParameterDirection.Input, true, 0, 0, null, DataRowVersion.Default, bytBLOBData));
                     }

接下来..是读取...

string sql = "select photo from studentinfo where studentid = " + this.Tag.ToString();
             OleDbCommand cmd = new OleDbCommand(sql, connection1);
             if (Convert.DBNull != cmd.ExecuteScalar())
                 pictureBox1.Image = Image.FromStream(new MemoryStream((Byte[])cmd.ExecuteScalar()));//读取长二进制为图片..