$box（查询谓词运算操作符）

定义

$box

Specifies a rectangle for a geospatial $geoWithin query to return documents that are within the bounds of the rectangle, according to their point-based location data. When used with the $box operator, $geoWithin returns documents based on grid coordinates and does not query for GeoJSON shapes.

To use the $box operator, you must specify the bottom left and top right corners of the rectangle in an array object:

{
  <location field>: {
     $geoWithin: {
        $box: [
          [ <bottom left coordinates> ],
          [ <upper right coordinates> ]
        ]
     }
  }
}

重要

如果使用经度和纬度，请先指定经度。

行为

查询用平面几何图形计算距离。

Applications can use $box without having a geospatial index. However, geospatial indexes support much faster queries than the unindexed equivalents.

Only the 2d geospatial index supports $box.

例子

以下示例查询返回框中具有以下点的所有文档：[ 0 , 0 ]、[ 0 , 100 ]、[ 100 , 0 ] 和 [ 100 , 100 ]。

db.places.find( {
   loc: { $geoWithin: { $box:  [ [ 0, 0 ], [ 100, 100 ] ] } }
} )