Introduction to Geospatial Queries in MongoDB

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1 ! Geometriske Spøringer Hans Kristian Flaatten @Starefossen Bergen MongoDB & NoSQL User Group Tirsdag 15. desember 2015 Bergen og Hordaland Turlag

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Geometriske indexer • Sfærisk (Spherical) • index: 2dsphere • data: GeoJSON • Flat (legacy) • index: 2d • data: coordinate pairs 2

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2dsphere • Introdusert i MongoDB v2.4.0 • http://geojson.org/ • coordinate-axis order: longitude, latitude • coordinate reference system: WGS84 datum 3

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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

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GeoJSON 5 { "type": "LineString", "coordinates": [ [100.0, 0.0], [101.0, 1.0], [102.0, 2.0] ], "properties": { "name": "Simple Line" } }

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Coordinate Reference System (CRS) • geoid • ellipsoid (spheroid) • Lokal: NAD1983, GDA94 • Global: WGS84, GRS80, International 1924 6

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7 geoid Ellipsoide globalt best passende til geoiden Ellipsoide regionalt tilpasset geoiden Best mulig passform

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topograﬁ geosenter b a 8 H h

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Geometriske Spøringer 9  $geoWithin  $geoIntersects <*>  $near

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2dsphere index 10 db.collection.createIndex({ : "2dsphere" });

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$geoWithin 11 $geoWithin: { $geometry: { type: <"Polygon" or "MultiPolygon">, coordinates: [ ] } }

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$geoWithin (improved) 12 $geoWithin: { $box: [ [ ], [ ] ] }

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$geoIntersects 13 $geoIntersects: { $geometry: { type: <"GeoJSON object type">, coordinates: [ ] } }

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$near 14 $near: { $geometry: { type: "Point", coordinates: coordinates: [ , ] }, $maxDistance: , $minDistance: }