SQL SOUNDEX function

The SQL Server SOUNDEX String Function returns the four-digit Soundex code of the user-specified character expressions and its syntax is

SELECT SOUNDEX(Character_Expression)
FROM [Source]

This SQL Soundex function converts any given character’s expression into a four-digit code based on the string sound. It will place the first character from the character_expression as the first digit, and the remaining are numbers. In some cases, it will add 0’s to the end to complete the four-digit code.

SQL SOUNDEX Function Example

The following list of examples will help you to understand the Soundex function.

DECLARE @Str VARCHAR(50)
SET @Str = 'SQL Server'

SELECT SOUNDEX(@Str) AS SoundText 

SELECT SOUNDEX('SQL') AS SoundText 

SELECT SOUNDEX('Sales') AS SoundText 

SELECT SOUNDEX('Suresh') AS SoundText

In this String method example, we are going to return the SOUNDEX code of the multiple characters expressions, along with the difference. I suggest you refer to the Difference Function article SQL Server to understand the same.

SELECT SOUNDEX('SQL Server') AS Code1,
       SOUNDEX('SQL') AS Code11,
	   DIFFERENCE('SQL Server', 'SQL') AS Difference1 

SELECT SOUNDEX('SQL') AS Code2,
       SOUNDEX('Suresh') AS Code22,
	   DIFFERENCE('SQL', 'Suresh') AS Difference2

SELECT SOUNDEX('Suresh') AS Code3,
       SOUNDEX('Srsh') AS Code33,
	   DIFFERENCE('Suresh', 'Srsh') AS Difference3