SQL Server SOUNDEX() Function

The SOUNDEX() function in SQL Server generates a four-character code that represents the phonetic sound of a given string. This is incredibly useful for finding similar-sounding words even if they are spelled slightly differently.

SOUNDEX(): Definition and Usage

SOUNDEX() is often used for fuzzy string matching, where you want to find strings that sound alike but may not have exact spelling matches. This is especially helpful when dealing with data entry errors or variations in spelling. The function produces a four-character code; strings with similar-sounding codes are considered phonetically similar.

Related Function

The DIFFERENCE() function compares the SOUNDEX codes of two strings to determine their phonetic similarity.

Syntax


SOUNDEX(expression)

Parameter Values

Parameter	Description
`expression`	The string to be evaluated. This can be a literal string, a column name, or any other expression resulting in a string value. This is required.

Examples

Comparing Similar-Sounding Words

This example compares "Juice" and "Jucy" to illustrate how SOUNDEX() generates phonetic codes.

Syntax


SELECT SOUNDEX('Juice'), SOUNDEX('Jucy');

Output


J200 J200

Comparing Dissimilar Words

This shows a comparison between "Juice" and "Banana".

Syntax


SELECT SOUNDEX('Juice'), SOUNDEX('Banana');

Output


J200 B520