Aggregate.geoNear(options: Object): Aggregate

支持端：小程序 2.7.4 起, 云函数 0.8.1 起

聚合阶段。将记录按照离给定点从近到远输出。

参数

options: Object

属性类型默认值必填说明
nearGeoPoint是GeoJSON Point，用于判断距离的点
sphericaltrue是必填，值为 true
limitnumber否限制返回记录数
maxDistancenumber否距离最大值
minDistancenumber否距离最小值
queryObject否要求记录必须同时满足该条件（语法同 where）
distanceMultipliernumber否返回时在距离上乘以该数字
distanceFieldstring是存放距离的输出字段名，可以用点表示法表示一个嵌套字段
includeLocsstring否列出要用于距离计算的字段，如果记录中有多个字段都是地理位置时有用
keystring否选择要用的地理位置索引。如果集合由多个地理位置索引，则必须指定一个，指定的方式是指定对应的字段

返回值

Aggregate

API 说明

  • geoNear 必须为第一个聚合阶段
  • 必须有地理位置索引。如果有多个，必须用 key 参数指定要使用的索引。

示例

假设集合 attractions 有如下记录：

  1. {
  2.   "_id": "geoNear.0",
  3.   "city": "Guangzhou",
  4.   "docType": "geoNear",
  5.   "location": {
  6.     "type": "Point",
  7.     "coordinates": [
  8.       113.30593,
  9.       23.1361155
  10.     ]
  11.   },
  12.   "name": "Canton Tower"
  13. },
  14. {
  15.   "_id": "geoNear.1",
  16.   "city": "Guangzhou",
  17.   "docType": "geoNear",
  18.   "location": {
  19.     "type": "Point",
  20.     "coordinates": [
  21.       113.306789,
  22.       23.1564721
  23.     ]
  24.   },
  25.   "name": "Baiyun Mountain"
  26. },
  27. {
  28.   "_id": "geoNear.2",
  29.   "city": "Beijing",
  30.   "docType": "geoNear",
  31.   "location": {
  32.     "type": "Point",
  33.     "coordinates": [
  34.       116.3949659,
  35.       39.9163447
  36.     ]
  37.   },
  38.   "name": "The Palace Museum"
  39. },
  40. {
  41.   "_id": "geoNear.3",
  42.   "city": "Beijing",
  43.   "docType": "geoNear",
  44.   "location": {
  45.     "type": "Point",
  46.     "coordinates": [
  47.       116.2328567,
  48.       40.242373
  49.     ]
  50.   },
  51.   "name": "Great Wall"
  52. }
  1. const $ = db.command.aggregate
  2. db.collection('attractions').aggregate()
  3.   .geoNear({
  4.     distanceField: 'distance', // 输出的每个记录中 distance 即是与给定点的距离
  5.     spherical: true,
  6.     near: db.Geo.Point(113.3089506, 23.0968251),
  7.     query: {
  8.       docType: 'geoNear',
  9.     },
  10.     key: 'location', // 若只有 location 一个地理位置索引的字段，则不需填
  11.     includeLocs: 'location', // 若只有 location 一个是地理位置，则不需填
  12.   })
  13.   .end()

返回结果如下：

  1. {
  2.   "_id": "geoNear.0",
  3.   "location": {
  4.     "type": "Point",
  5.     "coordinates": [
  6.       113.30593,
  7.       23.1361155
  8.     ]
  9.   },
  10.   "docType": "geoNear",
  11.   "name": "Canton Tower",
  12.   "city": "Guangzhou",
  13.   "distance": 4384.68131486958
  14. },
  15. {
  16.   "_id": "geoNear.1",
  17.   "city": "Guangzhou",
  18.   "location": {
  19.     "type": "Point",
  20.     "coordinates": [
  21.       113.306789,
  22.       23.1564721
  23.     ]
  24.   },
  25.   "docType": "geoNear",
  26.   "name": "Baiyun Mountain",
  27.   "distance": 6643.521654040738
  28. },
  29. {
  30.   "_id": "geoNear.2",
  31.   "docType": "geoNear",
  32.   "name": "The Palace Museum",
  33.   "city": "Beijing",
  34.   "location": {
  35.     "coordinates": [
  36.       116.3949659,
  37.       39.9163447
  38.     ],
  39.     "type": "Point"
  40.   },
  41.   "distance": 1894750.4414538583
  42. },
  43. {
  44.   "_id": "geoNear.3",
  45.   "docType": "geoNear",
  46.   "name": "Great Wall",
  47.   "city": "Beijing",
  48.   "location": {
  49.     "type": "Point",
  50.     "coordinates": [
  51.       116.2328567,
  52.       40.242373
  53.     ]
  54.   },
  55.   "distance": 1928300.3308822548
  56. }