Based on the pi ratio, the earth's radius coefficient and the longitude and latitude of the search point, search for data within N kilometers of the search point in the data table.
CREATE TABLE `location` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(50) NOT NULL, `longitude` decimal(13,10) NOT NULL, `latitude` decimal(13,10) NOT NULL, PRIMARY KEY (`id`), KEY `long_lat_index` (`longitude`,`latitude`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
insert into location(name,longitude,latitude) values ('广州东站',113.332264,23.156206), ('林和西',113.330611,23.147234), ('天平架',113.328095,23.165376);mysql> select * from `location`; +----+--------------+----------------+---------------+| id | name | longitude | latitude | +----+--------------+----------------+---------------+| 1 | 广州东站 | 113.3322640000 | 23.1562060000 | | 2 | 林和西 | 113.3306110000 | 23.1472340000 || 3 | 天平架 | 113.3280950000 | 23.1653760000 | +----+--------------+----------------+---------------+
Search point coordinates: Times Square 113.323568, 23.146436
6370.996Kilometer is the radius of the earth
Formula for calculating the coordinate distance between two points on the sphere
C = sin(MLatA)sin(MLatB)cos(MLonA-MLonB) cos(MLatA)cos(MLatB)
Distance = RArccos(C)*Pi180
According to the calculation formula, the query statement is as follows:
select * from `location` where ( acos(sin(([#latitude#]*3.1415)/180) * sin((latitude*3.1415)/180) + cos(([#latitude#]*3.1415)/180) * cos((latitude*3.1415)/180) * cos(([#longitude#]*3.1415)/180 - (longitude*3.1415)/180))*6370.996)<=1;
Execute the query:
mysql> select * from `location` where ( -> acos( -> sin((23.146436*3.1415)/180) * sin((latitude*3.1415)/180) + -> cos((23.146436*3.1415)/180) * cos((latitude*3.1415)/180) * cos((113.323568*3.1415)/180 - (longitude*3.1415)/180) -> )*6370.996 -> )<=1; +----+-----------+----------------+---------------+| id | name | longitude | latitude | +----+-----------+----------------+---------------+| 2 | 林和西 | 113.3306110000 | 23.1472340000 | +----+-----------+----------------+---------------+
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