Algorithm For Determining City Name W/o Internet Access?

I have a database of Cities my application supports. This includes following: Name. Center coordinates. Nearest cities my app support are pretty far away. Algorithm I want to im

Solution 1:

You can use the following logic to get the distance between two lat long

(This is for oracle)

DISTANCE   =  (NVL(Radius,0) *ACOS((sin(NVL(Lat1,0) / DegToRad) *SIN(NVL(Lat2,0) / DegToRad)) +
    (COS(NVL(Lat1,0) / DegToRad) *COS(NVL(Lat2,0) / DegToRad) *Cos(Nvl(Lon2,0) / Degtorad - Nvl(Lon1,0)/ Degtorad))))

Where DEGTORAD = 57.29577951;

Radius= 6387.7;

May be, similar logic can be implemented via a raw Query in SQLite DB.

The distance can be calculated and ranked and sorted based on least distance.