SOUNDEX function

The SOUNDEX function returns the American Soundex value consisting of the first letter of the input string followed by a 3–digit encoding of the sounds that represent the English pronunciation of the string that you specify. For example, Smith and Smyth have the same Soundex value.

Syntax

SOUNDEX(string)

Arguments

string

You specify a CHAR or VARCHAR string that you want to convert to an American Soundex code value.

Return type

VARCHAR(4)

Usage notes

The SOUNDEX function converts only English alphabetical lowercase and uppercase ASCII characters, including a–z and A–Z. SOUNDEX ignores other characters. SOUNDEX returns a single Soundex value for a string of multiple words separated by spaces.

SELECT SOUNDEX('AWS Amazon');
            
+---------+
| soundex |
+---------+
| A252    |
+---------+

SOUNDEX returns an empty string if the input string doesn't contain any English letters.

SELECT SOUNDEX('+-*/%');

+---------+
| soundex |
+---------+
|         |
+---------+

Examples

To return the Soundex value for Amazon, use the following example.

SELECT SOUNDEX('Amazon');

+---------+
| soundex |
+---------+
| A525    |
+---------+

To return the Soundex value for smith and smyth, use the following example. Note that the Soundex values are the same.

SELECT SOUNDEX('smith'), SOUNDEX('smyth');

+-------+-------+
| smith | smyth |
+-------+-------+
| S530  | S530  |
+-------+-------+