Query a 2dsphere
Index
On this page
The following sections describe queries supported by the 2dsphere
index.
GeoJSON Objects Bounded by a Polygon
The $geoWithin
operator queries for location data found within a GeoJSON polygon. Your location data must be stored in GeoJSON format. Use the following syntax:
db.<collection>.find( { <location field> :
{ $geoWithin :
{ $geometry :
{ type : "Polygon" ,
coordinates : [ <coordinates> ]
} } } } )
The following example selects all points and shapes that exist entirely within a GeoJSON polygon:
db.places.find( { loc : { $geoWithin : { $geometry : { type : "Polygon" , coordinates : [ [ [ 0 , 0 ] , [ 3 , 6 ] , [ 6 , 1 ] , [ 0 , 0 ] ] ] } } } } )
Intersections of GeoJSON Objects
The $geoIntersects
operator queries for locations that intersect a specified GeoJSON object. A location intersects the object if the intersection is non-empty. This includes documents that have a shared edge.
The $geoIntersects
operator uses the following syntax:
db.<collection>.find( { <location field> :
{ $geoIntersects :
{ $geometry :
{ type : "<GeoJSON object type>" ,
coordinates : [ <coordinates> ]
} } } } )
The following example uses $geoIntersects
to select all indexed points and shapes that intersect with the polygon defined by the coordinates
array.
db.places.find( { loc : { $geoIntersects : { $geometry : { type : "Polygon" , coordinates: [ [ [ 0 , 0 ] , [ 3 , 6 ] , [ 6 , 1 ] , [ 0 , 0 ] ] ] } } } } )
Proximity to a GeoJSON Point
Proximity queries return the points closest to the defined point and sorts the results by distance. A proximity query on GeoJSON data requires a 2dsphere
index.
To query for proximity to a GeoJSON point, use either the $near
operator. Distance is in meters.
The $near
uses the following syntax:
db.<collection>.find( { <location field> :
{ $near :
{ $geometry :
{ type : "Point" ,
coordinates : [ <longitude> , <latitude> ] } ,
$maxDistance : <distance in meters>
} } } )
For examples, see $near
.
See also the $nearSphere
operator and the $geoNear
aggregation pipeline stage.
Points within a Circle Defined on a Sphere
To select all grid coordinates in a "spherical cap" on a sphere, use $geoWithin
with the $centerSphere
operator. Specify an array that contains:
-
The grid coordinates of the circle's center point
-
The circle's radius measured in radians. To calculate radians, see Calculate Distance Using Spherical Geometry.
Use the following syntax:
db.<collection>.find( { <location field> :
{ $geoWithin :
{ $centerSphere :
[ [ <x>, <y> ] , <radius> ] }
} } )
The following example queries grid coordinates and returns all documents within a 10 mile radius of longitude 88 W
and latitude 30 N
. The example converts the distance, 10 miles, to radians by dividing by the approximate equatorial radius of the earth, 3963.2 miles:
db.places.find( { loc : { $geoWithin : { $centerSphere : [ [ -88 , 30 ] , 10 / 3963.2 ] } } } )