This directory contains a module that implements the "Metaphone" code as
a PostgreSQL user-defined function. The Metaphone system is a method of
matching similar sounding names (or any words) to the same code.
Metaphone was invented by Lawrence Philips as an improvement to the popular
name-hashing routine, Soundex.
This metaphone code is from Michael Kuhn, and is detailed at
http://aspell.sourceforge.net/metaphone/metaphone-kuhn.txt
Code for this (including this help file!) was liberally borrowed from
the soundex() module for PostgreSQL.
There are two functions:
metaphone(text) : returns hash of a name
metaphone(text,int) : returns hash (maximum length of int) of name
---
To install it, first configure the main source tree, then run make;
make install in this directory. Finally, load the function definition
with psql:
psql -f PREFIX/share/contrib/metaphone.sql
The following are some usage examples:
SELECT text_metaphone('hello world!');
SELECT text_metaphone('hello world!', 4);
CREATE TABLE s (nm text)\g
insert into s values ('john')\g
insert into s values ('joan')\g
insert into s values ('wobbly')\g
select * from s
where text_metaphone(nm) = text_metaphone('john')\g
select nm from s a, s b
where text_metaphone(a.nm) = text_metaphone(b.nm)
and a.oid <> b.oid\g
CREATE FUNCTION text_mp_eq(text, text) RETURNS bool AS
'select text_metaphone($1) = text_metaphone($2)'
LANGUAGE 'sql'\g
CREATE FUNCTION text_mp_lt(text,text) RETURNS bool AS
'select text_metaphone($1) < text_metaphone($2)'
LANGUAGE 'sql'\g
CREATE FUNCTION text_mp_gt(text,text) RETURNS bool AS
'select text_metaphone($1) > text_metaphone($2)'
LANGUAGE 'sql';
CREATE FUNCTION text_mp_le(text,text) RETURNS bool AS
'select text_metaphone($1) <= text_metaphone($2)'
LANGUAGE 'sql';
CREATE FUNCTION text_mp_ge(text,text) RETURNS bool AS
'select text_metaphone($1) >= text_metaphone($2)'
LANGUAGE 'sql';
CREATE FUNCTION text_mp_ne(text,text) RETURNS bool AS
'select text_metaphone($1) <> text_metaphone($2)'
LANGUAGE 'sql';
DROP OPERATOR #= (text,text)\g
CREATE OPERATOR #= (leftarg=text, rightarg=text, procedure=text_mp_eq,
commutator=text_mp_eq)\g
SELECT *
FROM s
WHERE text_mp_eq(nm,'pillsbury')\g
SELECT *
from s
where s.nm #= 'pillsbury';
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