how to read byte stream from database in C#

while (dbDr_obj.HasRows == true)
{
dbDr_obj.Read ( );
someString = dbDr_obj.GetString ( 0 );

byte[] buffer = new byte[8192];
long read= 0;
long index = 0;

do
{
read = dbDr_obj.GetBytes ( 1, index, buffer, 0, buffer.Length );
m.Write(buffer, 0, (int)read);
index += read;
} //eof while
while (read > 0) ;


if (dbDr_obj.IsClosed == false)
{
dbDr_obj.Close ( ); //comm -- remember to close the DbReader obj otherwise
} //eof if (dbDr_obj.IsClosed == false)
break;
} //eof while