PDF file that is retrieved from database is incorrect

Good day guys hope you will help me on this,

Lately I am saving pdf files in MySQL database into BLOB Datatypes. Few days later

I discover how to retrieve the PDF Files that I saved from the database. But there is a problem,

When I open the pdf file that I retrieve. Error message shows that is in incorrect format and

it's not a pdf file. Below is my code for retrieving PDF File:

DataTable table = part.GetPartAttachment();

byte[] filedata = (byte[])table.Rows[0][0];

SaveFileDialog sfd = new SaveFileDialog();

string filetosave;

sfd.Filter = "(*.pdf)|*.pdf";

if (sfd.ShowDialog() != DialogResult.Cancel)

{

filetosave = sfd.FileName;

FileStream fs = new FileStream(filetosave,FileMode.Create,FileAccess.Write);

BinaryWriter bw = new BinaryWriter(fs);

bw.Write(filedata);

bw.Close();

}

Hope you'll help me on this masters