That (using the zip code digits) won't work. Zip codes are assigned by population density, not by distance. A big city might have several zip codes, although they'd all likely have the same first three digits, but check Manhattan for an example.
In our area, the core city (Hartford) and some of its suburbs have the same three digits (061), even though they have their own post offices; but there is a ring of suburbs that have a different prefix (060). It would be wrong to assume that all of the 060 suburbs are closer to each other than they are to the central city. I imagine that some of the farm-land areas cover a lot of territory with very few zip codes. I don't know how the mapping software does it, really. They must have big tables of some sort. Regards, Jerry Schwartz Global Information Incorporated 195 Farmington Ave. Farmington, CT 06032 860.674.8796 / FAX: 860.674.8341 -----Original Message----- From: Jesse [mailto:[EMAIL PROTECTED] Sent: Tuesday, August 29, 2006 4:31 PM To: MySQL List Subject: Zip Code & Distance This is not necessarily SQL Specific, but it will impact my MySQL application. Using the zip code, how can you determine what's in a (say) 50 mile radius. In other words, if I'm looking for schools within a 50 mile radius of my location (Zip Code 33881), How can I determine this by the zip code? I have seen lots of search engines that do this, but don't know how they determine the distance. I figured that I can use the first 4 digits as a match, then the first 3 digits which will be a little further away, but I don't know how accurate that would be. Does anyone have any ideas? Thanks, Jesse -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
