Query for Locations Near a Point on a Flat Surface

About this Task

• When specifying coordinate pairs in the $near operator, list the longitude first, and then latitude.

  • Valid longitude values are between -180 and 180, both inclusive.

  • Valid latitude values are between -90 and 90, both inclusive.

• Specify distance in the $maxDistance field in meters.

Before you Begin

1. Create the contacts collection:

   db.contacts.insertMany( [
      {
         name: "Evander Otylia",
         phone: "202-555-0193",
         address: [ 55.5, 42.3 ]
      },
      {
         name: "Georgine Lestaw",
         phone: "714-555-0107",
         address: [ -74, 44.74 ]
      }
   ] )

   The address field contains legacy coordinate pairs.

2. To query for location data with the $near operator, you must create a geospatial index on the field that contains the location data.

   Create a 2d index on the address field:

   db.contacts.createIndex( { address: "2d" } )

Procedure

Use $near to query the collection. The following $near query returns documents that have an address field within 50 meters of the coordinate pair [ -73.92, 40.78 ]:

db.contacts.find( {
   address: {
      $near: [ -73.92, 40.78 ],
      $maxDistance : 50
   }
} )

Output:

[
   {
     _id: ObjectId("640a3dd9c639b6f094b00e89"),
     name: 'Georgine Lestaw',
     phone: '714-555-0107',
     address: [ -74, 44.74 ]
   }
]

Results are sorted by distance from the queried point, from nearest to farthest.

Learn More

• $near

• $geoNear

• Geospatial Index Restrictions

• To perform proximity queries on a spherical surface, see Query for Locations Near a Point on a Sphere.