DIFFERENCE ( string-expression-1, string-expression-2  )

SMALLINT

The DIFFERENCE function compares the SOUNDEX values of two strings and evaluates the similarity between them, returning a value from 0 through 4, where 4 is the best match.

This function always returns some value. The result is NULL only if one of the arguments are NULL.

• SOUNDEX function [String]
• String functions

The following statement returns similarity between the words test and chest:

SELECT DIFFERENCE( 'test', 'chest' );