-- Requires: CREATE EXTENSION fuzzystrmatch;

-- Soundex: American English phonetic algorithm
SELECT name, SOUNDEX(name) AS soundex_code
FROM customers;

-- Find phonetically similar names
SELECT a.name, b.name, DIFFERENCE(a.name, b.name) AS phonetic_similarity
FROM customers a
CROSS JOIN customers b
WHERE a.cust_id < b.cust_id
  AND SOUNDEX(a.name) = SOUNDEX(b.name); -- same soundex = phonetically similar

-- Metaphone: more accurate than soundex
SELECT name, METAPHONE(name, 6) AS metaphone
FROM customers;