VB.NET MySQL blob saving fails for some files -

sometimes saving blob using vb.net mysql db fails. saving pdfs.

when open pdf on computer, works great. save db, , works find. retrieve pdf db again, save file, , can open it.

however acrobat reader not want open newly save pdf, saying file corrupt.

i not sure exactely have flaw in code. nice if help. thank you.

private function pupdateinvoice(byval uguid string, byval upath string) boolean      dim rawdata() byte     dim fs filestream      try         fs = new filestream(upath, filemode.open, fileaccess.read)          dim ifilesize uint32         ifilesize = fs.length          rawdata = new byte(ifilesize) {}         fs.read(rawdata, 0, ifilesize)         fs.close()          if not g_cnwebdb.ping             initmysql()         end if          dim sfilename$         sfilename = cleanfile(upath, false)          dim ssql         ssql = "update expenses set " & _             "expense_invoicename=@expense_invoicename," & _             "expense_invoicefilesize=@expense_invoicefilesize," & _             "expense_invoiceblob=@expense_invoiceblob," & _             "expense_invoicetype=@expense_invoicetype, " & _             "expense_invoiceexistsinguid=@expense_invoiceexistsinguid " & _             "where " & _             "expense_guid=@expense_guid"          dim cmd new mysqlcommand         cmd.connection = g_cnwebdb         cmd.commandtext = ssql         cmd.parameters.addwithvalue("expense_invoicename", sfilename)         cmd.parameters.addwithvalue("expense_invoicefilesize", ifilesize)         cmd.parameters.addwithvalue("expense_invoiceblob", rawdata)         cmd.parameters.addwithvalue("expense_invoicetype", einvoicetype.eit_digital)         cmd.parameters.addwithvalue("expense_invoiceexistsinguid", "")         cmd.parameters.addwithvalue("expense_guid", uguid)          cmd.executenonquery()          return true      catch ex exception         messagebox.show("there error: " & ex.message, "error", _             messageboxbuttons.ok, messageboxicon.error)     end try      return false  end function   private sub pshowpdf(byval uguid string)      if not g_cnwebdb.ping         initmysql()     end if      dim cmdsel new mysqlcommand("select * expenses expense_guid=" & apo(uguid), g_cnwebdb)     dim r mysqldatareader     r = cmdsel.executereader      if not r.hasrows         stop     end if      r.read()      dim filesize uint32     filesize = r.getuint32(r.getordinal("expense_invoicefilesize"))     dim rawdata() byte     rawdata = new byte(filesize) {}      r.getbytes(r.getordinal("expense_invoiceblob"), 0, rawdata, 0, filesize)     r.close()      dim spath$     spath = "m:\temp.pdf"     modio.deletefile(spath)      dim fs filestream     fs = new filestream(spath, filemode.openorcreate, fileaccess.write)     fs.write(rawdata, 0, filesize)     fs.close()      dim id integer     id = system.diagnostics.process.start(spath).id  end sub 

i chose "blob" column type in db. instead should have chosen "longblob".