How to search nearest place in array object in mongodb - mongodb

Question

the mongodb document 'contents' is
{
"_id" : ObjectId("57bd1ff410ea3c38386b9194"),
"name" : "4Fingers",
"locations" : [
{
"id" : "locations1",
"address" : "68 Orchard Rd, #B1-07 Plaza Singapura, Plaza Singapura, Singapura 238839",
"phone" : "[phone]",
"openhours" : "Sunday-Thursday: 11am - 10pm \nFriday/Saturday/Eve of PH*: 11am - 11pm",
"loc" : [
"1.300626",
"103.845061"
]
}
],
"comments" : [ ],
"modified" : 1472271793525,
"created" : 1472012276724,
"createdby" : "Admin",
"modifiedby" : "Admin",
"createdipaddress" : "localhost",
"modifiedipaddress" : null,
"types" : "Restaurant",
"category" : "FoodAndBeverages",
"logo" : "logo4Fingers.png",
"tags" : "western, chicken, restaurant, food, beverages"
}
I want to find the nearest place to my location that i get from HTML5 navigation. How do i query it? Data should be sorted in near to far order.
Thank you.

Answer 1

To query mongodb geospatial data first you need a geo spatial index on your location field.
Your location field is a string, it needs to be a numeric type, you need to update your data accordingly.
Create your index on numerical location data:
db.collection.createIndex( { "locations.loc" : "2d" });
Query:
var projection = {"locations.loc":1};
var query = {"locations.loc": {"$near":[1.300626, 103.845061], "$maxDistance": 0.5}};
db.collection.find(query, projection).pretty();
//result:
{
"_id" : ObjectId("57bd1ff410ea3c38386b9194"),
"locations" : [
{
"loc" : [
1.300626,
103.845061
]
}
]
}
var query2 = {"locations.loc": {"$near":[2.300626, 103.845061], "$maxDistance": 0.5}};
db.collection.find(query2, projection).pretty();
//result:
{}
The query result will be sorted always, with nearest as first document.

Answer 2

Thanks Sergiu Zaharie.
It's working.
Then how can i returned all the field instead of returning this field only.
{
"_id" : ObjectId("57bd1ff410ea3c38386b9194"),
"locations" : [
{
"loc" : [
103.845061,
1.300626
]
}
]
}
//edit
Solved.
i just clear the projection then it work like charm.
Thank you.