Use Aggregate with $near query - mongodb

Question

I am trying to run a query on a mongoDB and use $nearin the query. This query below works, but I need to aggrate based on LAT and LNG. I am trying to aggregate or get a count based on those that are within a certain distance to pickup_location.
I am using the below in a shell, NOT code.
HERE IS A RECORD:
{
"_id": {
"$oid": "5445ab058767000062"
},
"comment": null,
"dropoff_address": "XHgwMmB7fk1lRn59YFx4MDM=U2FsdGVkX19s3u4NEtImfofJzxnGreGpsna8qA4uVrq7exRDVy+zPn5UwDOj\nzpIs",
"dropoff_location": [
-97.816991,
30.189151
],
"pickup_address": "XHgwMmB7fk1lRn59YFx4MDM=U2FsdGVkX1/23mD3Vv3Nyf4/t+AEickIgOlkaxVp5y/e/5Ia2d3Z0OXtnejw\nrOK+ZPvxQontA9SS30t+MbUIrCMhndxpYcKNFm4xfOzRVxM=",
"pickup_location": [
-97.82075191025548,
30.20993147664687
],
"scheduled_request": false,
"status": "blah",
"timestamp_requested": {
"$date": "2014-10-21T00:38:28.990Z"
},
"total_owed_in_cents": 0,
"total_received_from_in_cents": 0,
"user_id": "5445a9000057"
}
THIS WORKS:
db.thing_requests.aggregate(
[
{$match: {total_received_in_cents: {$gt:1800}, requested_type: 'Blah' }},
{
$group:
{
_id: null,
average: { $avg: "$total_received_in_cents" }
}
}
]
)
NEED THIS ADDED TO WHAT WORKS ABOVE:
{
the_location: {
$near: {
$geometry: {
type: "Point" ,
coordinates: [ <longitude> , <latitude> ]
},
$maxDistance: <distance in meters>,
$minDistance: <distance in meters>
}
}
}
UPDATE:
The top query works. What I need is to say all the items that are aggregated I also need to be sure they are NEAR a certain LAT & LNG.
UPDATE 2:
Ran this query
db.thing_requests.aggregate([
{
$geoNear: {
near: { type: "Point", coordinates: [ -97.888,37.3222 ] },
distanceField: "dist.calculated",
maxDistance: 2,
minDistance :1,
query: {total_received_in_cents: {$gt:1800}, requested_type: 'Blah' },
includeLocs: "dist.location",
num: 5,
spherical: true
}
},
{
$group:
{
_id: "$user_id",
average: { $avg: "$total_received_from_requester_in_cents" }
}
}
])
RECEIVED THIS ERROR:
assert: command failed: {
"errmsg" : "exception: geoNear command failed: { ok: 0.0, errmsg: \"no geo indices for geoNear\" }",
"code" : 16604,
"ok" : 0
} : aggregate failed
Error: command failed: {
"errmsg" : "exception: geoNear command failed: { ok: 0.0, errmsg: \"no geo indices for geoNear\" }",
"code" : 16604,
"ok" : 0
} : aggregate failed
at Error (<anonymous>)
at doassert (src/mongo/shell/assert.js:11:14)
at Function.assert.commandWorked (src/mongo/shell/assert.js:254:5)
at DBCollection.aggregate (src/mongo/shell/collection.js:1278:12)
at (shell):1:23
2017-08-28T21:21:40.153-0500 E QUERY Error: command failed: {
"errmsg" : "exception: geoNear command failed: { ok: 0.0, errmsg: \"no geo indices for geoNear\" }",
"code" : 16604,
"ok" : 0
} : aggregate failed
at Error (<anonymous>)
at doassert (src/mongo/shell/assert.js:11:14)
at Function.assert.commandWorked (src/mongo/shell/assert.js:254:5)
at DBCollection.aggregate (src/mongo/shell/collection.js:1278:12)
at (shell):1:23 at src/mongo/shell/assert.js:13

Answer 1

Use $geoNear in first stage
db.thing_requests.aggregate([
{
$geoNear: {
near: { type: "Point", coordinates: [ long,lat ] },
distanceField: "dist.calculated",
maxDistance: 2,
minDistance :1,
query: {total_received_in_cents: {$gt:1800}, requested_type: 'Blah' },
includeLocs: "dist.location",
num: 5,
spherical: true
}
},
{
//use $group here
}
])
you can use $near too
db.thing_requests.find( {
the_location: {
$near: {
$geometry: {
type: "Point" ,
coordinates: [ <longitude> , <latitude> ]
},
$maxDistance: <distance in meters>,
$minDistance: <distance in meters>
}
},total_received_in_cents: {$gt:1800}, requested_type: 'Blah'
});
but in any case you need to specify a geospatial (2d,2dsphere) index on the "the_location" field
if you are using mongoose there is a simple way to do this
specify 2d or 2dsphere index like this in your schema
the_location: {
type: [Number], // format will be [ <longitude> , <latitude> ]
index: '2dsphere' // create the geospatial index
}
or use db command
db.collection.createIndex( { <location field> : "2dsphere" } )
for more perfer https://docs.mongodb.com/manual/geospatial-queries/