地理位置搜寻LBS，存储每个地点的经纬度坐标，搜寻附近的地点，建立地理位置索引可提高查询效率。mongodb地理位置索引，2d和2dsphere，对应平面和球面。
1.创建lbs集合存放地点坐标
use lbs; db.lbs.insert( { loc:{ type: "Point", coordinates: [113.332264, 23.156206] }, name: "广州东站" } ) db.lbs.insert( { loc:{ type: "Point", coordinates: [113.330611, 23.147234] }, name: "林和西" } ) db.lbs.insert( { loc:{ type: "Point", coordinates: [113.328095, 23.165376] }, name: "天平架" } ) 2.创建地理位置索引
db.lbs.ensureIndex( { loc: "2dsphere" } ) 3.查询附近的坐标当前位置为：时代广场，坐标：
113.323568, 23.146436
搜寻附近一公里内的点，由近到远排序
db.lbs.find( { loc: { $near:{ $geometry:{ type: "Point", coordinates: [113.323568, 23.146436] }, $maxDistance: 1000 } } } ) 搜寻结果：
复制代码 代码如下:
{ "_id" : ObjectId("556a651996f1ac2add8928fa"), "loc" : { "type" : "Point", "coordinates" : [ 113.330611, 23.147234 ] }, "name" : "林和西" }
php代码如下：
<?php // 连接mongodb function conn($dbhost, $dbname, $dbuser, $dbpasswd){ $server = "mongodb://".$dbuser.":".$dbpasswd."@".$dbhost."/".$dbname; try{ $conn = new MongoClient($server); $db = $conn->selectDB($dbname); } catch (MongoException $e){ throw new ErrorException("Unable to connect to db server. Error:" . $e->getMessage(), 31); } return $db; } // 插入坐标到mongodb function add($dbconn, $tablename, $longitude, $latitude, $name){ $index = array("loc"=>"2dsphere"); $data = array( "loc" => array( "type" => "Point", "coordinates" => array(doubleval($longitude), doubleval($latitude)) ), "name" => $name ); $coll = $dbconn->selectCollection($tablename); $coll->ensureIndex($index); $result = $coll->insert($data, array("w" => true)); return (isset($result["ok"]) && !empty($result["ok"])) ? true : false; } // 搜寻附近的坐标 function query($dbconn, $tablename, $longitude, $latitude, $maxdistance, $limit=10){ $param = array( "loc" => array( "$nearSphere" => array( "$geometry" => array( "type" => "Point", "coordinates" => array(doubleval($longitude), doubleval($latitude)), ), "$maxDistance" => $maxdistance*1000 ) ) ); $coll = $dbconn->selectCollection($tablename); $cursor = $coll->find($param); $cursor = $cursor->limit($limit); $result = array(); foreach($cursor as $v){ $result[] = $v; } return $result; } $db = conn("localhost","lbs","root","123456"); // 随机插入100条坐标纪录 for($i=0; $i<100; $i++){ $longitude = "113.3".mt_rand(10000, 99999); $latitude = "23.15".mt_rand(1000, 9999); $name = "name".mt_rand(10000,99999); add($db, "lbs", $longitude, $latitude, $name); } // 搜寻一公里内的点 $longitude = 113.323568; $latitude = 23.146436; $maxdistance = 1; $result = query($db, "lbs", $longitude, $latitude, $maxdistance); print_r($result); ?> 演示php代码，首先需要在mongodb的lbs中创建用户和执行auth。方法如下：
use lbs; db.createUser( { "user":"root", "pwd":"123456", "roles":[] } ) db.auth( { "user":"root", "pwd":"123456" } ) 计算两点地理坐标的距离功能：根据圆周率和地球半径系数与两点坐标的经纬度，计算两点之间的球面距离。
获取两点坐标距离：
<?php/** * 计算两点地理坐标之间的距离 * @param Decimal $longitude1 起点经度 * @param Decimal $latitude1 起点纬度 * @param Decimal $longitude2 终点经度 * @param Decimal $latitude2 终点纬度 * @param Int $unit 单位 1:米 2:公里 * @param Int $decimal 精度 保留小数位数 * @return Decimal */function getDistance($longitude1, $latitude1, $longitude2, $latitude2, $unit=2, $decimal=2){ $EARTH_RADIUS = 6370.996; // 地球半径系数 $PI = 3.1415926; $radLat1 = $latitude1 * $PI / 180.0; $radLat2 = $latitude2 * $PI / 180.0; $radLng1 = $longitude1 * $PI / 180.0; $radLng2 = $longitude2 * $PI /180.0; $a = $radLat1 - $radLat2; $b = $radLng1 - $radLng2; $distance = 2 * asin(sqrt(pow(sin($a/2),2) + cos($radLat1) * cos($radLat2) * pow(sin($b/2),2))); $distance = $distance * $EARTH_RADIUS * 1000; if($unit==2){ $distance = $distance / 1000; } return round($distance, $decimal);}// 起点坐标$longitude1 = 113.330405;$latitude1 = 23.147255;// 终点坐标$longitude2 = 113.314271;$latitude2 = 23.1323;$distance = getDistance($longitude1, $latitude1, $longitude2, $latitude2, 1);echo $distance."m"; // 2342.38m$distance = getDistance($longitude1, $latitude1, $longitude2, $latitude2, 2);echo $distance."km"; // 2.34km?> 