From: Peter Brawley
Date: October 20 2005 3:50am
Subject: Re: Spatial Extensions to make a Dealer Locator?
List-Archive: http://lists.mysql.com/mysql/190619
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Brian

 >I'm in the midst of the age-old problem of finding the right SQL to 
 >make a Dealer Locator by ZIP code. Like Steffan's posts from a
 >couple  weeks ago, I have the ZIP code data in one table with
 >latitudes and  longitudes, and the table of Dealers with ZIP codes
 >in a separate table.

For great circle distance given latitudes & longitudes you may find (as 
we did) that the current MySQL implementation of OpenGIS is 
simultaneously overkill (because of complexity) and underkill ( for 
features & maturity). There are several reliable formulas for great 
circle distance including a few quoted here.

PB



Brian Dunning wrote:

> I'm in the midst of the age-old problem of finding the right SQL to  
> make a Dealer Locator by ZIP code. Like Steffan's posts from a couple  
> weeks ago, I have the ZIP code data in one table with latitudes and  
> longitudes, and the table of Dealers with ZIP codes in a separate table.
>
> While researching this I came across a reference to MySQL's Spatial  
> Extensions:
> http://dev.mysql.com/doc/refman/5.0/en/spatial-extensions-in-mysql.html
>
> This is WAY over my head. The reference I found said these extensions  
> are "immature". I'm not even exactly sure what an extension is: does  
> it mean that my ISP (PowWeb) probably doesn't have it installed?
>
> Has anyone else who has tackled this application found the Spatial  
> Extensions to be useful, or is it better to stick with the basics and  
> go the route discussed in Steffan's recent thread?
>
> - Brian
>


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