C# GUID Byte Array (Oracle) vs Casting (SQL)

ORACLE
guid = HexEncoding.ToString((byte[])dt.Rows[0]["GUID"]);

public static string ToString(byte[] bytes)
{
string hexString = "";
for (int i = 0; i <>

SQL
Guid guid = ((Guid)dt.Rows[0]["GUID"]);
string strGuid = guid.toString();