Skip to main content


1. SOUNDEX Function

The SOUNDEX function in H2 database is used to generate a phonetic code for a given string. It is commonly used in database systems for fuzzy string matching.

2. Syntax

The syntax for the SOUNDEX function in H2 database is as follows:



  • string: The input string for which the phonetic code needs to be generated. It should be a character string.


  • The SOUNDEX function returns a four-character code (a string) representing the phonetic encoding of the input string.

3. Notes

  • The SOUNDEX function in H2 database follows the standard Soundex algorithm for generating phonetic codes.
  • The generated phonetic code can be used to compare strings for similarity, as strings with the same or similar phonetic codes are likely to sound alike.
  • The SOUNDEX function is case-insensitive, meaning it treats uppercase and lowercase characters as the same.
  • The SOUNDEX function only considers alphabetic characters and ignores any non-alphabetic characters in the input string.
  • If the input string is empty or consists only of non-alphabetic characters, the SOUNDEX function will return NULL.

4. Examples

Here are a few examples demonstrating the usage of the SOUNDEX function in H2 database:

Example 1 - Generating the phonetic code for a string:

SELECT SOUNDEX('H2 Database') AS phonetic_code;



Example 2 - Comparing strings using SOUNDEX:

SELECT column_name
FROM table_name
WHERE SOUNDEX(column_name) = SOUNDEX('search_string');

This example demonstrates how to use the SOUNDEX function to compare the phonetic codes of a column with a search string. It helps in finding similar sounding strings.

  • difference - Calculate the difference between two strings based on their SOUNDEX codes.
  • SOUNDEX_DISTANCE - Calculate the distance between two SOUNDEX codes.