$minDistance

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Definition定义

$minDistance

Filters the results of a geospatial $near or $nearSphere query to those documents that are at least the specified distance from the center point.将地理空间$near或$nearSphere查询的结果筛选到距离中心点至少指定距离的文档。

If $near or $nearSphere query specifies the center point as a GeoJSON point, specify the distance as a non-negative number in meters.如果$near或$nearSphere查询将中心点指定为GeoJSON点，请将距离指定为以米为单位的非负数。

If $nearSphere query specifies the center point as legacy coordinate pair, specify the distance as a non-negative number in radians. 如果$nearSphere查询将中心点指定为传统坐标对，请将距离指定为以弧度表示的非负数。$near can only use the 2dsphere index if the query specifies the center point as a GeoJSON point.如果查询将中心点指定为GeoJSON点，则$near只能使用2dsphere索引。

Examples示例

Use with $near与$near一起使用

Important重要

If specifying latitude and longitude coordinates, list the longitude first and then latitude:如果指定纬度和经度坐标，请先列出经度，然后列出纬度：

  • Valid longitude values are between -180 and 180, both inclusive.有效的经度值介于-180和180之间（包括两者）。
  • Valid latitude values are between -90 and 90, both inclusive.有效纬度值介于-90和90之间（包括两者）。

Consider a collection places that has a 2dsphere index.考虑一个具有2dsphere索引的集合places。

The following example returns documents that are at least 1000 meters from and at most 5000 meters from the specified GeoJSON point, sorted from nearest to farthest:以下示例返回距离指定GeoJSON点至少1000米、最多5000米的文档，从最近到最远排序：

db.places.find(
   {
     location:
       { $near :
          {
            $geometry: { type: "Point",  coordinates: [ -73.9667, 40.78 ] },
            $minDistance: 1000,
            $maxDistance: 5000
          }
       }
   }
)

Use with $nearSphere与$nearSphere一起使用

Consider a collection places that contains documents with a location field and has a 2dsphere index.考虑一个集合places，其中包含具有location字段和2dsphere索引的文档。

Then, the following example returns whose location is at least 1000 meters from and at most 5000 meters from the specified point, ordered from nearest to farthest:然后，以下示例返回其location距离指定点至少1000米，最多5000米，从最近到最远排序：

db.places.find(
   {
     location: {
        $nearSphere: {
           $geometry: {
              type : "Point",
              coordinates : [ -73.9667, 40.78 ]
           },
           $minDistance: 1000,
           $maxDistance: 5000
        }
     }
   }
)

For an example that specifies the center point as legacy coordinate pair, see $nearSphere有关将中心点指定为传统坐标对的示例，请参阅$nearSphere

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