What 'length' parameter should I pass to SqlDataReader.GetBytes()

Question

I have a SqlDataReader and need to read a varbinary(max) column from it using the SqlDataReader.GetBytes() method. This method populates a byte array and therefore needs to

Answer 1

You could probably do this. Found on MSDN. Probably it could server your purpose

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

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

 // Continue reading and writing while there are bytes beyond the size of the buffer.
  while (retval == bufferSize)
  {
    bw.Write(outbyte);
    bw.Flush();

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

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

http://msdn.microsoft.com/en-us/library/87z0hy49%28v=vs.71%29.aspx#Y132

Or this one

int ndx = rdr.GetOrdinal("");
            if(!rdr.IsDBNull(ndx))
           {
            long size = rdr.GetBytes(ndx, 0, null, 0, 0);  //get the length of data
            byte[] values = new byte[size];

            int bufferSize = 1024;
            long bytesRead = 0;
            int curPos = 0;

            while (bytesRead < size)
            {
                bytesRead += rdr.GetBytes(ndx, curPos, values, curPos, bufferSize);
                curPos += bufferSize;
            }
           }