ad949c2f65
I tested hex in a 1000w times for loop with random numbers， old hex avg time cost is 4.92 s，optimize hex avg time cost is 0.46 s which faster nearly 10x.
1.5 KiB
1.5 KiB
title, language
| title | language |
|---|---|
| unhex | en |
unhex
description
Syntax
VARCHAR unhex(VARCHAR str)
Enter a string, if the length of the string is 0 or an odd number, an empty string is returned;
If the string contains characters other than [0-9], [a-z], [A-Z], an empty string is returned;
In other cases, every two characters are a group of characters converted into hexadecimal, and then spliced into a string for output.
example
mysql> select unhex('@');
+------------+
| unhex('@') |
+------------+
| |
+------------+
mysql> select unhex('41');
+-------------+
| unhex('41') |
+-------------+
| A |
+-------------+
mysql> select unhex('4142');
+---------------+
| unhex('4142') |
+---------------+
| AB |
+---------------+
keyword
UNHEX