Syntax
------ 
SOUNDEX(str)
 
Description
----------- 
Returns a soundex string from str. Two strings that sound
almost the
same should have identical soundex strings. A standard
soundex string is four
characters long, but the SOUNDEX() function returns an
arbitrarily long
string. You can use SUBSTRING() on the result to get a
standard soundex
string. All non-alphabetic characters in str are ignored.
All
international alphabetic characters outside the A-Z range
are treated as
vowels.
 
Important: When using SOUNDEX(), you should be aware of the
following limitations:
This function, as currently implemented, is intended to work
well with
 strings that are in the English language only. Strings in
other languages may
 not produce reliable results.
 
Examples
-------- 
SOUNDEX('Hello');
+------------------+
| SOUNDEX('Hello') |
+------------------+
| H400 |
+------------------+
 
SELECT SOUNDEX('MariaDB');
+--------------------+
| SOUNDEX('MariaDB') |
+--------------------+
| M631 |
+--------------------+
 
SELECT SOUNDEX('Knowledgebase');
+--------------------------+
| SOUNDEX('Knowledgebase') |
+--------------------------+
| K543212 |
+--------------------------+
 
SELECT givenname, surname FROM users WHERE
SOUNDEX(givenname) = SOUNDEX("robert");
+-----------+---------+
| givenname | surname |
+-----------+---------+
| Roberto | Castro |
+-----------+---------+
 


URL: https://mariadb.com/kb/en/soundex/