If N_or_S is a number, returns a string representation of the hexadecimal value of N.
If N_or_S is a string, returns a hexadecimal string representation of N_or_S where each character in N_or_S is converted to two hexadecimal digits.
mysql> mysql> SELECT HEX(255); +----------+ | HEX(255) | +----------+ | FF | +----------+ 1 row in set (0.00 sec) mysql>
23.15.HEX | ||||
23.15.1. | HEX(N_or_S) | |||
23.15.2. | HEX('abc'); | |||
23.15.3. | SELECT HEX(CHAR(1,0)), HEX(CHAR(256)); | |||
23.15.4. | SELECT HEX(CHAR(1,0,0)), HEX(CHAR(256*256)); |