MongoDB GeoSpatial Feature
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MongoDB allows for geospatial queries on location data stored in collections. There are two main index types - 2d for flat geometry and 2dsphere for spherical geometry. Queries include proximity queries to find nearest points, intersection queries to find intersections with shapes, and inclusion queries to find points within shapes. The appropriate index type and query operators depend on whether location data is represented as legacy coordinate pairs or GeoJSON objects and whether distances are calculated on a flat plane or sphere.
![2d Query
db.<collection>.find( { <location field> :
{ $geoWithin :
{ $box|$polygon|$center : <coordinates>
} } } )
db.places.find( { loc :
{ $geoWithin :
{ $box : [ [ 0 , 0 ] ,
[ 100 , 100 ] ]
} } } )](https://image.slidesharecdn.com/mongodbgeospatialfeature-150520110327-lva1-app6891/85/MongoDB-GeoSpatial-Feature-19-320.jpg)
![db.places.find( { loc: { $geoWithin :
{ $center : [ [-74, 40.74 ] , 10 ]
} } } )
db.<collection>.find( { <location field> :
{ $near : [ <x> , <y> ]
} } )
db.<collection>.find( { loc: [ <x> , <y> ] } )](https://image.slidesharecdn.com/mongodbgeospatialfeature-150520110327-lva1-app6891/85/MongoDB-GeoSpatial-Feature-20-320.jpg)
![2dsphere Query
db.<collection>.find( { <location field> :
{ $geoWithin :
{ $geometry :
{ type : "Polygon" ,
coordinates : [ <coordinates> ]
} } } } )
db.places.find( { loc :
{ $geoWithin :
{ $geometry :
{ type : "Polygon" ,
coordinates : [ [[ 0 , 0 ] ,[ 3 , 6 ] ,[ 6 , 1 ] ,[ 0 , 0 ]] ]} } } } )](https://image.slidesharecdn.com/mongodbgeospatialfeature-150520110327-lva1-app6891/85/MongoDB-GeoSpatial-Feature-22-320.jpg)
![Intersection
db.<collection>.find( { <location field> :
{ $geoIntersects :
{ $geometry :
{ type : "<GeoJSON object type>" ,
coordinates : [ <coordinates> ]
} } } } )
db.places.find( { loc :
{ $geoIntersects :
{ $geometry :
{ type : "Polygon" ,
coordinates: [ [[ 0 , 0 ] ,[ 3 , 6 ] ,[ 6 , 1 ] ,[ 0 , 0 ]] ]} } } } )](https://image.slidesharecdn.com/mongodbgeospatialfeature-150520110327-lva1-app6891/85/MongoDB-GeoSpatial-Feature-23-320.jpg)
![Proximity
db.<collection>.find( { <location field> :
{ $near :
{ $geometry :
{ type : "Point" ,
coordinates : [ <longitude> , <latitude> ] } ,
$maxDistance : <distance in meters>
} } } )](https://image.slidesharecdn.com/mongodbgeospatialfeature-150520110327-lva1-app6891/85/MongoDB-GeoSpatial-Feature-24-320.jpg)
MongoDB GeoSpatial Feature
- 2. What is MongoDB GeoSpatial Feature?
- 3. MongoDB allows you to create index and queries to make operations on geospatial (location information) data
- 4. In order to define index, or execute query, you need to determine surface first
- 5. Surfaces
- 6. Spherical To calculate geometry over an Earth-like sphere, store your location data on a spherical surface and use 2dsphere index. MongoDB Reference
- 7. Store your location data as GeoJSON objects with this coordinate-axis order: longitude, latitude. The coordinate reference system for GeoJSON uses the WGS84 datum. MongoDB Reference
- 8. GeoJSON
- 10. Example Usage
- 11. Flat To calculate distances on a Euclidean plane, store your location data as legacy coordinate pairs and use a 2d index. MongoDB Reference
- 12. Query Operations
- 13. Inclusion MongoDB can query for locations contained entirely within a specified polygon. Inclusion queries use the $geoWithin operator. No index required, 2d and 2dsphere supports MongoDB Reference
- 14. Intersection MongoDB can query for locations that intersect with a specified geometry. These queries apply only to data on a spherical surface. These queries use the $geoIntersects operator. Index required, only 2dsphere supports MongoDB Reference
- 15. Proximity MongoDB can query for the points nearest to another point. Proximity queries use the $near operator. 2d or 2dsphere required MongoDB Reference
- 16. Index Types
- 17. 2d ● Calculations using flat geometry ● Legacy coordinate pairs (i.e., geospatial points on a flat coordinate system) ● Compound indexes with only one additional field, as a suffix of the 2d index field
- 18. 2d Index Creation db.collection.createIndex( { <location field> : "2d" } , { min : <lower bound> , max : <upper bound> } ) db.collection.createIndex( { loc : "2d" } , { min : -45 , max : 45 } )
- 19. 2d Query db.<collection>.find( { <location field> : { $geoWithin : { $box|$polygon|$center : <coordinates> } } } ) db.places.find( { loc : { $geoWithin : { $box : [ [ 0 , 0 ] , [ 100 , 100 ] ] } } } )
- 20. db.places.find( { loc: { $geoWithin : { $center : [ [-74, 40.74 ] , 10 ] } } } ) db.<collection>.find( { <location field> : { $near : [ <x> , <y> ] } } ) db.<collection>.find( { loc: [ <x> , <y> ] } )
- 21. 2dsphere Index Creation db.collection.createIndex( { <location field> : "2dsphere" } ) db.collection.createIndex( { loc : "2dsphere" } )
- 22. 2dsphere Query db.<collection>.find( { <location field> : { $geoWithin : { $geometry : { type : "Polygon" , coordinates : [ <coordinates> ] } } } } ) db.places.find( { loc : { $geoWithin : { $geometry : { type : "Polygon" , coordinates : [ [[ 0 , 0 ] ,[ 3 , 6 ] ,[ 6 , 1 ] ,[ 0 , 0 ]] ]} } } } )
- 23. Intersection db.<collection>.find( { <location field> : { $geoIntersects : { $geometry : { type : "<GeoJSON object type>" , coordinates : [ <coordinates> ] } } } } ) db.places.find( { loc : { $geoIntersects : { $geometry : { type : "Polygon" , coordinates: [ [[ 0 , 0 ] ,[ 3 , 6 ] ,[ 6 , 1 ] ,[ 0 , 0 ]] ]} } } } )
- 24. Proximity db.<collection>.find( { <location field> : { $near : { $geometry : { type : "Point" , coordinates : [ <longitude> , <latitude> ] } , $maxDistance : <distance in meters> } } } )
- 25. 2dsphere ● Calculations on a sphere ● GeoJSON objects and include backwards compatibility for legacy coordinate pairs ● Compound indexes with scalar index fields (i.e. ascending or descending) as a prefix or
- 26. geoHaystack An index is a special index that is optimized to return results over small areas. geoHaystack indexes improve performance on queries that use flat geometry.
- 27. Any Questions