visitor to my site could punch in their postal code, and find out how far
they are from another postal code. For example, AutoTrader has this feature
I believe to tell you how far the vehicle is from you. Dating sites have
them so you can do proximity searches.
Anyone have any ideas where I could start? I'm thinking the post office,
but if anyone else has suggestions, I'm open to hear them.
Thanks!Are you in the UK? Royal Mail has some address database products that
may meet your requirements:
http://www.royalmail.com/portal/rm/...40085&gear=shop
Other solutions exist too:
http://www.google.co.uk/search?biw=...yUK%7CcountryGB
--
David Portas
SQL Server MVP
--|||This company does mailing list software with that data in it:
http://www.melissadata.com/Lookups/|||Actually, no, I'm in North America (Canada). Sorry for not mentioning that.
"David Portas" <REMOVE_BEFORE_REPLYING_dportas@.acm.org> wrote in message
news:1120060282.670987.93490@.g14g2000cwa.googlegro ups.com...
> Are you in the UK? Royal Mail has some address database products that
> may meet your requirements:
> http://www.royalmail.com/portal/rm/...40085&gear=shop
> Other solutions exist too:
> http://www.google.co.uk/search?biw=...yUK%7CcountryGB
> --
> David Portas
> SQL Server MVP
> --|||Be aware of the limitations of these calculations. I have done something
similar with US zipcodes, same principle. Each zone has a latitude and
longitude associated with it. This point is known as a centroid which is a
representative point for the whole zone. If the zone is a square or a circle
the centroid would be right in the middle. For a very irregular zone the
centroid might not even be in the zone. Think of a doughnut shaped zone.
Then you calculate the distance between the 2 centroids. Imagine 2 100 mile
square zones side by side. The distance calculation would be 100 miles. The
2 interested parties could actually be across the street from each other
each in their own zone.
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