postgresql/contrib/fuzzystrmatch
Bruce Momjian c40cd3660f One of the web pages mentioned in dmetaphone.c has moved. Also fix
a few typos in comments.

The dictionaries I checked list "altho" as a variant of "although,"
but I didn't find any other instances of the former in the source
tree so I changed it.

Michael Fuhr
2005-09-30 22:38:44 +00:00
..
dmetaphone.c One of the web pages mentioned in dmetaphone.c has moved. Also fix 2005-09-30 22:38:44 +00:00
fuzzystrmatch.c One of the web pages mentioned in dmetaphone.c has moved. Also fix 2005-09-30 22:38:44 +00:00
fuzzystrmatch.h The attached patch implements the soundex difference function which 2005-01-26 08:04:04 +00:00
fuzzystrmatch.sql.in The attached patch implements the soundex difference function which 2005-01-26 08:04:04 +00:00
Makefile PGXS should be set with := not =, as specified in the documentation, 2005-09-27 17:13:14 +00:00
README.fuzzystrmatch The attached patch implements the soundex difference function which 2005-01-26 08:04:04 +00:00
README.soundex The attached patch implements the soundex difference function which 2005-01-26 08:04:04 +00:00

NOTE: Modified August 07, 2001 by Joe Conway. Updated for accuracy
	after combining soundex code into the fuzzystrmatch contrib
---------------------------------------------------------------------
The Soundex system is a method of matching similar sounding names
(or any words) to the same code.  It was initially used by the
United States Census in 1880, 1900, and 1910, but it has little use
beyond English names (or the English pronunciation of names), and
it is not a linguistic tool.

When comparing two soundex values to determine similarity, the
difference function reports how close the match is on a scale
from zero to four, with zero being no match and four being an
exact match.

The following are some usage examples:

SELECT soundex('hello world!');

SELECT soundex('Anne'), soundex('Ann'), difference('Anne', 'Ann');
SELECT soundex('Anne'), soundex('Andrew'), difference('Anne', 'Andrew');
SELECT soundex('Anne'), soundex('Margaret'), difference('Anne', 'Margaret');

CREATE TABLE s (nm text)\g

insert into s values ('john')\g
insert into s values ('joan')\g
insert into s values ('wobbly')\g
insert into s values ('jack')\g

select * from s
where soundex(nm) = soundex('john')\g

select a.nm, b.nm from s a, s b
where soundex(a.nm) = soundex(b.nm)
and a.oid <> b.oid\g

CREATE FUNCTION text_sx_eq(text, text) RETURNS bool AS
'select soundex($1) = soundex($2)'
LANGUAGE 'sql'\g

CREATE FUNCTION text_sx_lt(text,text) RETURNS bool AS
'select soundex($1) < soundex($2)'
LANGUAGE 'sql'\g

CREATE FUNCTION text_sx_gt(text,text) RETURNS bool AS
'select soundex($1) > soundex($2)'
LANGUAGE 'sql';

CREATE FUNCTION text_sx_le(text,text) RETURNS bool AS
'select soundex($1) <= soundex($2)'
LANGUAGE 'sql';

CREATE FUNCTION text_sx_ge(text,text) RETURNS bool AS
'select soundex($1) >= soundex($2)'
LANGUAGE 'sql';

CREATE FUNCTION text_sx_ne(text,text) RETURNS bool AS
'select soundex($1) <> soundex($2)'
LANGUAGE 'sql';

DROP OPERATOR #= (text,text)\g

CREATE OPERATOR #= (leftarg=text, rightarg=text, procedure=text_sx_eq,
commutator = #=)\g

SELECT *
FROM s
WHERE text_sx_eq(nm,'john')\g

SELECT *
FROM s
WHERE s.nm #= 'john';

SELECT *
FROM s
WHERE difference(s.nm, 'john') > 2;