Algorithm to find all Latitude Longitude locations within a certain distance from a given Lat Lng location

Question

Given a database of places with Latitude + Longitude locations, such as 40.8120390, -73.4889650, how would I find all locations within a given distance of a specific locatio

Answer 1

Based on the current user's latitude, longitude and the distance you wants to find,the sql query is given below.

SELECT * FROM(
    SELECT *,(((acos(sin((@latitude*pi()/180)) * sin((Latitude*pi()/180))+cos((@latitude*pi()/180)) * cos((Latitude*pi()/180)) * cos(((@longitude - Longitude)*pi()/180))))*180/pi())*60*1.1515*1.609344) as distance FROM Distances) t
WHERE distance <= @distance

@latitude and @longitude are the latitude and longitude of the point. Latitude and longitude are the columns of distances table. Value of pi is 22/7