实现 $near 查询时出现 MongoDB 错误

Question

示例 MongoDB 文档

{
 "_id":"5adedaad0bd4134kb0",
 "url":"https://iscon.cdnalign.com/t51.288515/s640x640e35/10249200241120_2108192950_n.jpg?ig_cache_key=MTEYUTB1NDgxN",
 "description":"#funinthesun",
 "locationName":"Calamari",
 "statusValue":1,
 "reason":"Related to travel",
 "category":["park"],
 "geo": {
       "index":"Point",
       "coord":[29.123024,77.1999]
  }

我想根据与特定点的距离获取文档。

这是我正在使用的查询，以便文档根据距离来。

询问

var collection = db.collection('myData');
collection.ensureIndex({"geo.index":"Point"});
collection.find({ 
  geo :{
       $near : {
          $geometry : {   
             index : "Point" ,
             coord : [30.564058, 76.44762696]
          },
       $maxDistance : 100
      }
   }
}

这向我展示了这个错误:- {"name":"MongoError","message":"geo near query $geometry argument: { index:\"Point\", coord: [ 4.27326978424058, 30.4439024447627 ] } Point 必须是数组或对象", "waitedMS":0,"ok":0,"errmsg":"geo near query $geometry argument: { index:\"Point\", coord: [ 4.27326978424058, 30.4439024447627 ] } 点必须是一个数组或对象”，“代码”:2}

Answer 1

如果您查看 $near 文档 https://docs.mongodb.com/manual/reference/operator/query/near/你会发现这里有两个问题:

1. 您需要一个 2dsphere 类型的索引，以便对 GPS 字段进行地理空间查询
2. 地理空间点必须具有名称坐标属性，而不是坐标

这是你的代码的正确版本，应该可以工作

var collection = db.collection('myData');
collection.ensureIndex({"geo":"2dsphere"});
collection.find({ 
  geo :{
   $near : {
      $geometry : {   
         index : "Point" ,
         coordinates : [30.564058, 76.44762696]
        },
     $maxDistance : 100
    }
  }
})