Geographical or location-based searching

[notionlogic]

I've done some searching in the forums with little success so I thought it worth posting a question to see what others have done and/or may be able to help with!

I'm trying to find the best approach for handling location-based searches (e.g. by post code or zip code). All information I've found to date seems to indicate that longitude/latitude are the things to use and that it requires some fancy work either in the query or in the PHP code that processes the results. But there my knowledge ends...🙁

The search I'm thinking of would require the results to be listed in order of distance (closest first and then those further away) from a specified geographical location. I believe I can handle most of this but could do with some advice or assistance with calculating the distance and then sorting the results.

Can anyone help? Even some links to tutorials, examples and such like would be great - I don't mind figuring it out for myself if I just know where to start!

[barand]

There are complicated trigonometrical algorithms on the internet for calculating exact distances given two positions of lat. and long. but if you just need relative distances for a sort, simple Pythagoras should do.

Read your rsults into an array, add an extra element for each row containing the calculated distance and sort array then display results.