SELECT UUIDNumToString(toFixedString(unhex('0123456789ABCDEF0123456789ABCDEF' AS hex) AS bytes, 16) AS uuid_binary) AS uuid_string, hex(UUIDStringToNum(uuid_string)) = hex AS test1, UUIDStringToNum(uuid_string) = bytes AS test2; SELECT UUIDNumToString(toFixedString(unhex(materialize('0123456789ABCDEF0123456789ABCDEF') AS hex) AS bytes, 16) AS uuid_binary) AS uuid_string, hex(UUIDStringToNum(uuid_string)) = hex AS test1, UUIDStringToNum(uuid_string) = bytes AS test2; SELECT hex(UUIDStringToNum('01234567-89ab-cdef-0123-456789abcdef')); SELECT hex(UUIDStringToNum(materialize('01234567-89ab-cdef-0123-456789abcdef'))); SELECT '01234567-89ab-cdef-0123-456789abcdef' AS str, UUIDNumToString(UUIDStringToNum(str)), UUIDNumToString(UUIDStringToNum(toFixedString(str, 36))); SELECT materialize('01234567-89ab-cdef-0123-456789abcdef') AS str, UUIDNumToString(UUIDStringToNum(str)), UUIDNumToString(UUIDStringToNum(toFixedString(str, 36)));