Calculate the distance between U.S. zip codes and find all zip codes within a given distance of a known zip code.
This project was started as a port to PHP 5 of a zip code class I wrote in 2005 for PHP 4. It also provides improvements based on suggestions from users of the original code.
The ZipCode class is based on a MySQL table or view with the following fields:
zip_code_id int(11) PRIMARY KEY
zip_code varchar(5) UNIQUE KEY
city varchar(50)
county varchar(50)
state_name varchar(50)
state_prefix varchar(2)
area_code varchar(3)
time_zone varchar(50)
lat float
lon float
While the name of this table can be specified by the mysql_table class property,
the default table name is zip_code.
Original Database (obsolete)
The original zip code database was derived from 2000 U.S. Census data and manually tweaked over the years when a zip code was missing or incorrect. This database is known to have some missing and inaccurate zip codes.
You can find the SQL script with the entire zip_code table in
/data/obsolute/zip_code.sql. If you do not have access to your database from
the command line, such as using phpMyAdmin, you will have to split the script
into multiple files and upload them one at a time.
New Databases
There are numerous sources for U.S. zip code databases. Some are free and some
can be purchased. You can use one of these databases by either copying the
necessary fields from the source table to the zip_code table using a
SELECT INTO statement or by creating a view with the CREATE VIEW
statement.
See example.php for example usage. You can see a live demo on my personal
website (uses the obsolete data): PHP-ZipCode Example.