最近的纬度和经度位置

Question

I just have latitude and longitude of a store, now I want to find out all the stores near by in 1 hour drive or say at 10 KM distance.

I have table as,

Id, storeName, store_lat, store_lng

Say I have selected lat and lng of store 1 and I want to find out all the nearby stores. How to do that using php/mysql.

I have checked many post on SO but when I am running query, it's returning 0 results all the time.

Please help, thanks!

Answer 1

One approach is to take your input lat/long pair, create a range, then query for all records that fall in that range:

Distance = 0.1; // Range in degrees (0.1 degrees is close to 11km)
LatN = lat + Distance;
LatS = lat - Distance;
LonE = lon + Distance;
LonW = lon - Distance;

...Query DB with something like the following:
SELECT *
FROM table_name
WHERE 
(store_lat BETWEEN LatN AND LatS) AND
(store_lon BETWEEN LonE AND LonW)

The query should find everything where the stored lat is less than LatN and greater than LatS, and where the stored lon is less than LonE and greater than LonW.

You might then do a real distance calcuation for the returned results because the above search gives you a box, and locations in the corner will be greater than 0.1 degrees away, as the crow flies.

Use a map API with directions to get the driving distance, if "as the crow flies" isn't good enough.