根据经纬度查询方圆5公里数据信息

sql:

SELECT app_station_hdr.*

FROM app_station_hdr

WHERE getDistance(station_Lng, station_Lat, :lon, :lat) < 50000

	AND del_flag = 0

LIMIT 10

数据库函数：

CREATE DEFINER=root@% FUNCTION getDistance(

     lng1 float(10,7) 

    ,lat1 float(10,7)

    ,lng2 float(10,7) 

    ,lat2 float(10,7)

) RETURNS double

begin

    declare d double;

    declare radius int;

    set radius = 6378140; #假设地球为正球形，直径为6378140米

    set d = (2ATAN2(SQRT(SIN((lat1-lat2)PI()/180/2)   

        SIN((lat1-lat2)PI()/180/2)+   

        COS(lat2PI()/180)COS(lat1*PI()/180)   

        SIN((lng1-lng2)PI()/180/2)   

        SIN((lng1-lng2)PI()/180/2)),   

        SQRT(1-SIN((lat1-lat2)*PI()/180/2)   

        SIN((lat1-lat2)PI()/180/2)   

        +COS(lat2PI()/180)COS(lat1*PI()/180)   

        SIN((lng1-lng2)PI()/180/2)   

        SIN((lng1-lng2)PI()/180/2))))*radius;

    return d;

end