UNHEX

Description

The unhex function is used to convert a hexadecimal string back into the original string. It converts every two hexadecimal characters into one byte.

Syntax

UNHEX(<str>)

Parameters

Parameter	Description
<str>	The hexadecimal character string

Return Value

If the input string has a length of 0 or is odd, it returns an empty string. If the string contains characters other than [0-9], [a-f], or [A-F], it returns an empty string. In other cases, every two characters are converted to their hexadecimal representation and concatenated into a string for output.

Examples

select unhex('@');

+------------+
| unhex('@') |
+------------+
|            |
+------------+

select unhex('41');

+-------------+
| unhex('41') |
+-------------+
| A           |
+-------------+

select unhex('4142');

+---------------+
| unhex('4142') |
+---------------+
| AB            |
+---------------+