It might seem a dumb question to you guys. I have one SQL table with one binary column. It has some data in binary format.
e.g. 0x9A8B9D9A002020202020202020202020<
It really depends on which encoding was used when you originally converted from string to binary:
byte[] binaryString = (byte[])reader[1];
// if the original encoding was ASCII
string x = Encoding.ASCII.GetString(binaryString);
// if the original encoding was UTF-8
string y = Encoding.UTF8.GetString(binaryString);
// if the original encoding was UTF-16
string z = Encoding.Unicode.GetString(binaryString);
// etc