UNHEX

Syntax

UNHEX(str)

Purpose

UNHEX() converts hexadecimal numbers in the str string to bytes, and return a binary string.

Characters in the str string must fall in the following ranges: 0 to 9, A to F, and a to f. If the string contains any non-hexadecimal characters, the function returns NULL.

If str is a BINARY column with any values padded with 0x00 bytes, the function also returns NULL. For a numeric parameter N, UNHEX(N) is not the reverse operation of HEX(N). In this case, you need to use CONV(HEX(N),16,10).

Note that you can specify the --binary-as-hex parameter in the string for connection with the client. This parameter indicates that a binary string is represented in the hexadecimal equivalent.

Examples

obclient> SELECT UNHEX('4f6365616e42617365');
+-----------------------------+
| UNHEX('4f6365616e42617365') |
+-----------------------------+
| OceanBase                   |
+-----------------------------+
1 row in set

obclient> SELECT X'4f6365616e42617365';
+-----------------------+
| X'4f6365616e42617365' |
+-----------------------+
| OceanBase             |
+-----------------------+
1 row in set