In DB2 the HEX function converts a string to its hexadecimal representation. In SQL Server you can use CONVERT expressions with appropriate styles.
DB2:
-- Get hexadecimal representation of 'abc' SELECT HEX('abc') FROM sysibm.sysdummy1; # 616263
SQL Server:
-- Get hexadecimal representation of 'abc' using style 2 of CONVERT function SELECT CONVERT(VARCHAR, CONVERT(VARBINARY, 'abc'), 2); # 616263
Note that if you use style 1 in SQL Server, hexadecimal string contains 0x and style 0 (or absence of style parameter) converts the string back to its ASCII form:
SQL Server:
-- With style 1 the hexadecimal string includes 0x SELECT CONVERT(VARCHAR, CONVERT(VARBINARY, 'abc'), 1); # 0x616263 -- If style is 0 or absent the string is converted back to 'abc' SELECT CONVERT(VARCHAR, CONVERT(VARBINARY, 'abc'), 0); # abc
For more information, see IBM DB2 to SQL Server Migration.