how to download file from mdf database in c#

Question

i m currently working on project doing file management, and i just finish the code for upload file into my database(.mdf) table, however i have no idea how to download the file back to my folder(or anywhere else). I see people do download from ASP.Net, OR web sql database, but i wish if someone could tell me how to download it from a mdf database.

private void find_Click(object sender, EventArgs e)
{
  OpenFileDialog dlg = new OpenFileDialog();
  if (dlg.ShowDialog() == DialogResult.OK)
  {
   string Path = dlg.FileName.ToString();
   PathBox.Text = Path;
   PicBox.location = Path;
  }
}

private void save_Click(object sender, eventargs e) 
{ 
  byte[] Doc = null;
  Filestream fs = new FileStream(this.PathBox.Text, FileMode.Open, FileAccess.Read);
  BinaryReader br = new BinaryReader(fs);
  Doc = br.ReadBytes((int)fs.Length);

  string DS = "datasource = localDB ......";
  string Insertcmd = "insert into ......";
  MySqlConnection conn = new MySqlConnection(DS);
  MySqlCommand cmd = new MySqlCommand(Insertcmd, conn);
  MySqlDataReader msdr;

  try
  {
      conn.Open();
      cmd.Parameter.Add(new MySqlParameter("@Document", Doc));

      msdr = cmd.ExecuteReader();
      MessageBox.Show("file saved");
      While (msdr.Read())
      {
      }
   catch (Exception ex)
    {
    }
}

could someone give me a code that is able to download from .mdf database? or even any hint will be very helpful

thanks

Select the file from the database and write the byte array to disk, something like : http://stackoverflow.com/questions/381508/can-a-byte-array-be-written-to-a-file-in-c Search for 'write byte array to disk'. — GrandMasterFlush, Sep 29 '15 at 09:15
@GrandMasterFlush thank you very much, that really helps a lot :) — UnseenRoad, Sep 29 '15 at 13:01
@GrandMasterFlush Hi, i have a question, could you please check this link: http://stackoverflow.com/questions/32939079/value-cannot-be-null-parameter-name-bytes-suggestion-please — UnseenRoad, Oct 05 '15 at 07:22

score 0 · Answer 1 · answered Sep 29 '15 at 09:53

0

HI It seems that you are saving the file in a binary format (BLOB ) object ? So when you want to show the image after getting from Database you could read it using a memory stream and show it. or maybe use context.Response.BinaryWrite() to output the image.

http://csharpdotnetfreak.blogspot.com/2009/07/display-images-gridview-from-database.html might be helpful.

answered Sep 29 '15 at 09:53

m5c

567
8
13

thanks for reply, i m not sure if i m saving it as BLOB -- still learning how to use C#, but mostly this is for PDF document and Word documents, which will contain both text and pictures. I will try your code to see if i can output the file :p – UnseenRoad Sep 29 '15 at 13:04

how to download file from mdf database in c#

1 Answers1