Get the shortest distance from a point

Question

I have this table in sqlite

Locations
ID
Lat ( latitude)
Lon ( longitude) 
Type
Name
City

I have for example 100 records what I need is to

Answer 1

Though this is not a best option.
Let you are trying to figure out shortest distance within N mile/km radious for fixed no of locations/your location table data are not changing regularly.
Add another column Distance_Index (DI) a self multi reference key ArrayType. Once run a procedure and update the DI with ID in ascending order accoording to distance from this DI. Now from next time onwords distance is with you. just make a query to the database and use it.

Now, in your problem no of location are less within N, then DI will not be too much long.Just as an opinion.

Answer 2

Distance between two points: ((x1 - x2) ^ 2 + (y1 - y2) ^ 2) ^ 0.5. However, distance between these points are straight lines. Most likely, there are variables like local vs highway, not to mention one-way streets and waterways, where you need to find the nearest bridge. Therefore, I suggest using Google and Bing maps api. The are free for a limited number of searches.