problem with max_distance

[Maciej Gębarski]

Hi i have a problem with queries data using mongoengine.

I create two models

class Alarm(mongoengine.Document):
    added = mongoengine.DateTimeField()
    title = mongoengine.StringField()
    tracks = mongoengine.ListField(mongoengine.EmbeddedDocumentField(Track))

    meta = {
        'indexes': [[("tracks.location", "2dsphere")]]
    }

class Track(mongoengine.EmbeddedDocument):
    created_on = mongoengine.DateTimeField()
    location = mongoengine.PointField()

from shell i add one row :

db.alarm.insert({"title": "Warszawa", "tracks": [{"location": {"type": "Point", "coordinates": [21.01666, 52.233333]}}]})

Ok now in mongo shell i try find.

first return none second find:

>db.alarm.find({'tracks.location': {$near: {$geometry: {"type": "Point", coordinates: [18.068611, 59.329444]}, $maxDistance: 810997}}})
>

> db.alarm.find({'tracks.location': {$near: {$geometry: {"type": "Point", coordinates: [18.068611, 59.329444]}, $maxDistance: 810998}}})
{
 "_id" : ObjectId("53ef89626dda06655a57a342"), "title" : "Warszawa",
"tracks" : [ { "location" : { "type" : "Point", "coordinates" : [
21.01666, 52.233333 ] } } ] }

And i is ok.


But when i try in django shell:

 Alarm.objects(tracks__location__near = {"coordinates":[ 21.01666, 52.233333 ] , "type": "Point"}, tracks__location__max_distance=810998)

i get:

<repr(<mongoengine.queryset.queryset.QuerySet at 0x7ff3a50e8a10>) failed: pymongo.errors.OperationFailure: database error: Can't canonicalize query: BadValue geo near accepts just one argument when querying for a GeoJSON point. Extra field found: $maxDistance: 810998>

[Gonzalo Infante]

Had any luck solving the problem? I'm stuck with the same issue.

[Gonzalo Infante]

So far, this workaround is the only one that has worked for me. Use a raw query like this:

models.Incident.objects(__raw__={'location':{'$near':{'$geometry':{'type': "Point", 'coordinates': [lat, lon]},'$maxDistance': distance}}})

Just in case (regarding MongoEngine):

When using MongoEngine I had problems with variable naming inside the model I was trying to save. The variable containing the location was called loc, but that would throw the error you mentioned:

<repr(<mongoengine.queryset.queryset.QuerySet at 0x7ff3a50e8a10>) failed: pymongo.errors.OperationFailure: database error: Can't canonicalize query: BadValue geo near accepts just one argument when querying for a GeoJSON point. Extra field found: $maxDistance: 810998>

After changing the name to anything else it would not show the error above, instead it would show another error regarding max_distance parameter:

OperationFailure: database error: Can't canonicalize query: BadValue geo near accepts just one argument when querying for a GeoJSON point. Extra field found: $maxDistance: 111308

This is the query in Flask:

models.Incident.objects(location__near=[lat, lon], location__max_distance=distance)

[Juan Diego Restrepo]

Hi Gonzalo or anyone else, any luck with this problem?. I'm using mongoengine 0.8.7 with pymongo 2.8 and I'm getting the same error. Raw query works fine.