MongoDB spatial query - error unable to find index or no results

Question

I am having trouble while executing some spatial queries in MongoDb. I have a collection "cities15000" for which every record has this format

"_id" : ObjectId("5624aefe4728347a51b1d751"),
"geonameid" : "292932",
"name" : "Ajman",
"asciiname" : "Ajman",
"latitude" : "25.41111",
"longitude" : "55.43504",
"feature_code" : "PPLA",
"country_code" : "AE",
"population" : "226172",
"elevation" : "",
"timezone" : "Asia/Dubai",
"geography" : {
    "type" : "Point",
    "loc" : [ 
        "55.43504", 
        "25.41111"
    ]
} 

I have created a 2dsphere index db.cities15000.ensureIndex({loc : '2dsphere'}) and then i tried to get results using $near or $geonear.

While using $near db.cities15000.find({loc: {$near: [55.400 ,25.400]} }) i get this error message

Unable to execute query: error processing query...n planner returned error: unable to find index for $geoNear query"

which means that i have a wrong index (i think).

But then when i use db.runCommand({geoNear: "cities15000",near: { type: "Point", coordinates: [ 55.400 ,25.400 ] },spherical: true}) i get:

{
"results" : [],
"stats" : {
    "nscanned" : 0,
    "objectsLoaded" : 0,
    "avgDistance" : NaN,
    "maxDistance" : 0.0000000000000000,
    "time" : 0
},
"ok" : 1.0000000000000000
} 

which means that it doesn't find anything near (false). there are many similar topics but i have tried what is proposed there and nothing worked.

Answer 1

you have an error in index creation and the query:

according to your json schema there is no loc but instead there is "geography.loc"

i.e.

db.cities15000.find({loc: {$near: [55.400 ,25.400]} })

should be something like

db.cities15000.find({"geography.loc": {$near: [55.400 ,25.400]} })