One suggestion is to use the geo functionality of Postgres.... We use postgres to calculate city, state, and/or country by using the geo functions in postgresql.
I would really suggest using postgres for your calculations. You can pass the lat and long and have postgres give you the intersection of these and reference a table that has the zip codes.... B i g D o g ----- Original Message ----- From: "Brandon Pearcy" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, July 04, 2002 9:33 AM Subject: [PHP] Postal / Zip Code Proximity Search > Hello, > I have a couple of questions with respect to creating a postal / > zip code proximity search that is remotely accurate. The system I am > using now is OK for small distances, but is terrible at calculating > large distances. > > What I have is a database of establishments and their corresponding > latitudes and longitudes, and I need to have users enter their own > postal / zip code, and have the system calculate which establishments > fall into a set range ($range) from their location. Not only does it > need to find the establishments, it needs to calculate the distances > (straight line, of course). > > Now, I have dug through the PHP archives, but there is no single > clear explanation of how to do this, from beginning to end. I will > start by putting down what I need, and then maybe other people can > contribute to this and in the end we will have the solution, nice and > tidy, in one place. > > *** NOTE: I know doing this in PHP will be SLOW, but I do not want to > write a MySQL user-defined function and recompile it and blah, blah, > blah... (unless someone wants to cover that aspect!!! :D) > > Step 1: Take the postal / zip code that the user entered, and > search the national postal / zip code database (which I already have) > and return its corresponding latitude and longitude ($userLat and > $userLong). > > Step 2: ??? > > Step 3: Return the establishments information to the user, complete > with the distances to them, ordered by smallest distance to largest. > > > > If you can't help me out, maybe you can direct me to some online > tutorials on this topic! > > Thanks in Advance! > -- > -------------------------- > Brandon Pearcy > Internet Technician > > Bowes Online > -------------------------- > phone: 1-780-532-1110 ext. 265 > fax: 1-780-532-2120 > [EMAIL PROTECTED] > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
