Manuplate Excel file with OLEDB, with file streams instead of physical file

Question

Earlier I was reading excel file located on file system through Microsoft.Jet.OLEDB.4.0, and that was working fine, But now my client has told me that place excel file into a database table as BLOB column and read that file from that column and hide one workbook by manipulating that memory string directly.

Please help me out from this problem?

Answer 1

Create a temp with the BLOB contents and replace the BLOB when done.

string fileName = Path.GetTempFileName();
using (var stream = File.OpenWrite(fileName))
  stream.Write(blobContents);

// open excel with oledb
// and do your processing

using (var stream = File.OpenRead(fileName))
{
   var buffer = new byte[stream.Length];
   stream.Read(buffer, 0, stream.Length);

   //save blob
}