In Oracle, you can use TO_NUMBER function with x format to represent a hex constant (literal). In SQL Server, you can use the prefix 0x followed by hexadecimal digits.
Oracle:
-- Represent the hexadecimal constant ABC and use it in an expression SELECT TO_NUMBER('ABC', 'xxx') + 10 FROM dual;
SQL Server:
-- Represent the hexadecimal constant ABC and use it in an expression SELECT 0xABC + 10;
Oracle 11g R2 SQL Language Reference
Microsoft SQL Server 2012 - Books Online