ASP.NET

// string
file_name = Path.GetFileName(uploadResume.PostedFile.FileName);
file_extension = Path.GetExtension(uploadResume.PostedFile.FileName);

switch (file_extension)
{
    case ".pdf": document_type = "application/pdf"; break;
    case ".doc": document_type = "application/vnd.ms-word"; break;
    case ".docx": document_type = "application/vnd.ms-word"; break;
    case ".gif": document_type = "image/gif"; break;
    case ".png": document_type = "image/png"; break;
    case ".jpg": document_type = "image/jpg"; break;
    case ".jpeg": document_type = "image/jpg"; break;
}

// calculate size of file;
int file_size = uploadResume.PostedFile.ContentLength;

// create array to read the file into it;
byte[] document_binary = new byte[file_size];
uploadResume.PostedFile.InputStream.Read(document_binary, 0, file_size);

sql_command.Parameters.AddWithValue("param_resume_format", document_type).MySqlDbType = MySqlDbType.VarChar;
sql_command.Parameters.Add("param_resume_data", MySqlDbType.Blob, file_size).Value = document_binary;

sql_connection = new MySqlConnection(ConfigurationManager.ConnectionStrings["SQLdb"].ConnectionString);
sql_connection.Open();
sql_command = new MySqlCommand("sp_get_resume_by_id", sql_connection);
sql_command.CommandType = CommandType.StoredProcedure;
sql_command.Parameters.Add("param_resume_id", MySqlDbType.Int32).Value = resume_id;
sql_reader = sql_command.ExecuteReader();
sql_reader.Read();

if (sql_reader.HasRows)
{
    file_name = sql_reader["resume_id"].ToString() + sql_reader["resume_ext"].ToString();
    byte[] document_binary = (byte[])sql_reader["resume_data"];

    FileStream file_stream = new FileStream(@"C:\Temp\" + file_name, FileMode.Create);
    file_stream.Write(document_binary, 0, document_binary.Length);
    file_stream.Close();
    file_stream.Dispose();

    txtResume.Visible = true;
}

protected void Button1_Click(object sender, EventArgs e)
    {
        for (int i = 0; i < GridView1.Rows.Count; i++)
        {

            CheckBox chbox = GridView1.Rows[i].Cells[0].FindControl("CheckBox1") as CheckBox;

            if (chbox.Checked == true)
            {
                string conn = ConfigurationManager.ConnectionStrings["Test_T3ConnectionString2"].ConnectionString;
                SqlConnection con = new SqlConnection(conn);
                string query = "select prod_name,price from products where prod_id = '" + GridView1.Rows[i].Cells[1].Text + "'";
                SqlCommand cmd = new SqlCommand(query, con);
                SqlDataAdapter da = new SqlDataAdapter(cmd);
                DataTable dt = new DataTable();
                da.Fill(dt);

                GridView2.DataSource = dt;
                GridView2.DataBind();
            }

        }
    }