I was wondering if there are any examples that consist on basic geolocation input and database retrieval of given inputs within a certain area, preferably the user's current location.
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2 Answers
Here's a quick overview of geospatial queries in MongoDB:
You have to insert location information in your collection via 2D array
db.example.insert( {"location": [x,y], "category": "restaurant"})Set up a geospatial indexes on the collection by indicating the location field with "2d" option.
db.example.ensureIndex( { "location" : "2d" } )Now the collection will have an index which all geospatial queries will be done against.
To query for locations nearby a point (i.e. the user's current location), use the find() command with
$nearoperand on the location field giving the point coordinates (i.e. 100, 100.)db.example.find( { "location": { $near : [100, 100] } } )To find users current location, you would need higher level application support to get the user's current information.
For more information:
MongoDB documentation: http://www.mongodb.org/display/DOCS/Geospatial+Indexing
The
$nearoperator: http://docs.mongodb.org/manual/reference/operators/#_S_near
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I don't have enough reputation to comment on the answer below, so had to post another answer:
ensureIndex() has been replaced with createIndex().
See the docs.
