데이터베이스에서 BLOB 값 가져오기

  
// Assumes that connection is a valid SqlConnection object.
SqlCommand command = new SqlCommand(
  "SELECT pub_id, logo FROM pub_info", connection);

// Writes the BLOB to a file (*.bmp).
FileStream stream;                          
// Streams the BLOB to the FileStream object.
BinaryWriter writer;                        

// Size of the BLOB buffer.
int bufferSize = 100;                   
// The BLOB byte[] buffer to be filled by GetBytes.
byte[] outByte = new byte[bufferSize];  
// The bytes returned from GetBytes.
long retval;                            
// The starting position in the BLOB output.
long startIndex = 0;                    

// The publisher id to use in the file name.
string pubID = "";                     

// Open the connection and read data into the DataReader.
connection.Open();
SqlDataReader reader = command.ExecuteReader(CommandBehavior.SequentialAccess);

while (reader.Read())
{
  // Get the publisher id, which must occur before getting the logo.
  pubID = reader.GetString(0);  

  // Create a file to hold the output.
  stream = new FileStream(
    "logo" + pubID + ".bmp", FileMode.OpenOrCreate, FileAccess.Write);
  writer = new BinaryWriter(stream);

  // Reset the starting byte for the new BLOB.
  startIndex = 0;

  // Read bytes into outByte[] and retain the number of bytes returned.
  retval = reader.GetBytes(1, startIndex, outByte, 0, bufferSize);

  // Continue while there are bytes beyond the size of the buffer.
  while (retval == bufferSize)
  {
    writer.Write(outByte);
    writer.Flush();

    // Reposition start index to end of last buffer and fill buffer.
    startIndex += bufferSize;
    retval = reader.GetBytes(1, startIndex, outByte, 0, bufferSize);
  }

  // Write the remaining buffer.
  writer.Write(outByte, 0, (int)retval - 1);
  writer.Flush();

  // Close the output file.
  writer.Close();
  stream.Close();
}

// Close the reader and the connection.
reader.Close();
connection.Close();

앞서 MSDN 예제로 저장된 이미지를 다시 가져와 BMP파일로 저장한다.

http://msdn.microsoft.com/ko-kr/library/87z0hy49(VS.80).aspx