Introduction to Geospatial Queries in MongoDB

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1. 1 ! Geometriske Spøringer Hans Kristian Flaatten @Starefossen Bergen MongoDB & NoSQL User Group Tirsdag 15. desember 2015 Bergen og Hordaland Turlag
2. Geometriske indexer • Sfærisk (Spherical) • index: 2dsphere • data: GeoJSON • Flat (legacy) • index: 2d • data: coordinate pairs 2
3. 2dsphere • Introdusert i MongoDB v2.4.0 • http://geojson.org/ • coordinate-axis order: longitude, latitude • coordinate reference system: WGS84 datum 3
4. GeoJSON • Point (v2.4.0) • LineString (v2.4.0) • Polygon (v2.4.0) • MultiPoint (v2.4.0) • MultiLineString (v2.6.0) • MultiPolygon (v2.6.0) • GeometryCollection (v2.6.0) 4
5. GeoJSON 5 { "type": "LineString", "coordinates": [ [100.0, 0.0], [101.0, 1.0], [102.0, 2.0] ], "properties": { "name": "Simple Line" } }
6. Coordinate Reference System (CRS) • geoid • ellipsoid (spheroid) • Lokal: NAD1983, GDA94 • Global: WGS84, GRS80, International 1924 6
7. 7 geoid Ellipsoide globalt best passende til geoiden Ellipsoide regionalt tilpasset geoiden Best mulig passform
8. topografi geosenter b a 8 H h
9. Geometriske Spøringer 9  $geoWithin <Polygon>  $geoIntersects <*>  $near <Point>
10. 2dsphere index 10 db.collection.createIndex({ <location field> : "2dsphere" });
11. $geoWithin 11 $geoWithin: { $geometry: { type: <"Polygon" or "MultiPolygon">, coordinates: [ <coordinates> ] } }
12. $geoWithin (improved) 12 $geoWithin: { $box: [ [ <bottom left coordinates> ], [ <upper right coordinates> ] ] }
13. $geoIntersects 13 $geoIntersects: { $geometry: { type: <"GeoJSON object type">, coordinates: [ <coordinates> ] } }
14. $near 14 $near: { $geometry: { type: "Point", coordinates: coordinates: [<lon> , <lat>] }, $maxDistance: <distance in meters>, $minDistance: <distance in meters> }