$box¶
- $box¶
1.4 新版功能.
The $box operator specifies a rectangle for a geospatial $geoWithin query. The query returns documents that are within the bounds of the rectangle, according to their point-based location data. The $box operator returns documents based on grid coordinates and does not query for GeoJSON shapes.
The query calculates distances using flat (planar) geometry. The 2d geospatial index supports the $box operator.
To use the $box operator, you must specify the bottom left and top right corners of the rectangle in an array object. Use the following syntax:
{ <location field> : { $geoWithin : { $box : [ [ <bottom left coordinates> ] , [ <upper right coordinates> ] ] } } }
重要
If you use longitude and latitude, specify longitude first.
The following example query returns all documents that are within the box having points at: [ 0 , 0 ], [ 0 , 100 ], [ 100 , 0 ], and [ 100 , 100 ].
db.places.find( { loc : { $geoWithin : { $box : [ [ 0 , 0 ] , [ 100 , 100 ] ] } } } )
在 2.2.3 版更改: Applications can use $box without having a geospatial index. However, geospatial indexes support much faster queries than the unindexed equivalents. Before 2.2.3, a geospatial index must exist on a field holding coordinates before using any of the geospatial query operators.