Query polygons $geowithin $box mongodb doesn't return anything

问题

Guys I am trying to query all the polygons inside by bounding box but it simply returns 0.. It should be returning many polygons!

Alternatively I try to query a much larger bounding box and nothing happens!

My query is:

{
 geometry: 
    { $geoWithin: 
        { $box:  
            [ [-73.995762,40.764826], [-73.934034,40.802038] ] 
        } 
    }                       
}

Notice that the very same query returns a valid result for geometries of type Point

回答1:

to query all the polygons inside by bounding box but it simply returns 0

The $box operator for $geoWithin only supports documents based on grid coordinates and does not support GeoJSON shapes format.

the very same query returns a valid result for geometries of type Point

Depending on your documents structure, and how you are querying them, this is probably treated as being grid coordinates i.e. {geometry: [<long>, <lat>]} This may not have worked for your polygons document because GeoJSON Polygons require an extra array wrapper. i.e. [[ [<long>, <lat>] ]] invalidating the grid coordinates format.

If your documents are in GeoJSON format, and you would like to select an area, you could utilise $geometry instead.

db.places.find(
   {
     'geometry': {
       $geoWithin: {
          $geometry: {
             type : "Polygon" ,
             coordinates: [ [ [ 0, 0 ], [ 3, 6 ], [ 6, 1 ], [ 0, 0 ] ] ]
          }
       }
     }
   }
)

Worth noting that MongoDB Compass geospatial visualisation currently (v1.6) does not support GeoJSON yet.

回答2:

Here goes the answer:

$box do work with GeoJSON, but not with polygons! You need to generate a geometry with the $box instead.

Also, it always has to has the start point and point, so a 4-point polygon will have 5 coordinate tuples

BUT it gets trickier, it has to follow the right hand rule (anticlockwise).

TESTING GEOJSON WITH $BOX AND POINTS

my query {geometry: { $geoWithin: { $box: [ [-71.934034,38.764826], [-75.995762,43.802038] ] } }}

来源：https://stackoverflow.com/questions/42405589/query-polygons-geowithin-box-mongodb-doesnt-return-anything