Zip Code

Manat

Hello all,

If I have a table with all our major retailers and the store's zip codes, and if I have an online store finder wherein the user enters their zip code, clicks submit and all the zip codes close to the zip code they entered appear, how would I do this?

There is no web service as the table is on my production server and it's not inventory based.

I would apreciate any help.

thanks
MK

bastien

usually you have lat and long in the db, use that to calc the distance

see here for sample

Manat

Hi,

But that link is only if I have longitude and latitude information.
I don't, all I have is zip code information.

I want to display all stores located near the zip code that the user entered. It's all zip code based, I have no longitude or lattitude information.

Is there any way to do this? How do most sites do it?

Thanks
MK

bastien

third party tools are commonly used...see here

here

AstroTeg

You will need to get the zip codes' lat and long values.

See, by using trig, you can determine the distance between two points. But a zip code itself does not contain any location information. Its just a code used by the USPS. What you need is something like:

zip, x, y
12345, 1, 4

54321, 3, 6

Here, there is 2 zips and some X and Y data. From this, you can determine the distance between the two points by finding the slope (which is really just distance): (Y2-Y1)/(X2-X1)

Trick is the earth is not flat but sort of round. So this is where the trig comes in, but the concept is the same. The other difference is your X and Y values are latitude and longitude . I have an equation I use, but I don't have it in front of me.

For lat/long coordinates, you have a few choices. If you're looking for dead accurate info, you'll want to contact the USPS. They sell a CD. I don't remember what the cost is. Its not very cheap if I remember correctly. The 2nd option is to hit up the census web site. They keep track of lat/long via a zip code, but the trick is their zip codes don't usually match perfectly with USPS's. They explain in a little more detail the problems and why they don't. If you can live with this, you can extract the data yourself and insert it into you database. It'll require some creativity to get the data, but it can be (and has been) done.

sneakyimp

What about simple zip code comparison? zip codes that are geographically close are also numerically close. I know that United Parcel Service published a rate schedule based on this principle. Does anyone know heuristic guides about this?

AstroTeg

You may want to check out this post: http://www.phpbuilder.com/board/showthread.php?s=&threadid=10272986

I have C code posted which plugs into MySQL which will do this. Or check out the Postgres solution (PostGIS I believe).

You would need something like this to perform a search. Otherwise, you'd have to load up your search query with all the math involved to do the calculations. And then you'd have to do a 2nd pass on the results to determine the desired range.