根据用户经纬度,sql计算距离并排序
Posted dcxmaozi
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根据经纬度计算距离
- public class DistanceUtil {
- // 地球平均半径
- private static final double EARTH_RADIUS = 6378137;
- // 把经纬度转为度(°)
- private static double rad(double d) {
- return d * Math.PI / 180.0;
- }
- /**
- * 根据两点间经纬度坐标(double值),计算两点间距离,单位:千米
- * @author ershuai
- * @param lng1
- * @param lat1
- * @param lng2
- * @param lat2
- * @return
- */
- public static double getDistance(double lng1, double lat1, double lng2, double lat2) {
- double radLat1 = rad(lat1);
- double radLat2 = rad(lat2);
- double a = radLat1 - radLat2;
- double b = rad(lng1) - rad(lng2);
- double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2) + Math.cos(radLat1) * Math.cos(radLat2) * Math.pow(Math.sin(b / 2), 2)));
- s = s * EARTH_RADIUS;
- s = s / 1000;
- DecimalFormat df = new DecimalFormat("#.00");
- s = Double.parseDouble(df.format(s));
- return s;
- }
- public static void main(String[] args) {
- double distance1 = getDistance(104.046115, 30.6030110000, 104.074666, 30.611842);
- System.out.println("Distance is: " + distance1 + " km");
- }
- }
sql 查询
- SELECT
- es_name,
- es_lon,
- es_lat,
- ROUND(
- 6378.138 * 2 * ASIN(
- SQRT(
- POW(
- SIN(
- (
- 30.611842 * PI() / 180 - es_lat * PI() / 180
- ) / 2
- ),
- 2
- ) + COS(30.611842 * PI() / 180) * COS(es_lat * PI() / 180) * POW(
- SIN(
- (
- 104.074666 * PI() / 180 - es_lon * PI() / 180
- ) / 2
- ),
- 2
- )
- )
- ) * 1000
- ) AS distance_um
- FROM
- c_ershuai
- ORDER BY
- distance_um ASC
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