6.19. Geospatial Functions

6.19. Geospatial Functions

Presto Geospatial functions support the SQL/MM specification.They are compliant with the Open Geospatial Consortium’s (OGC) OpenGIS Specifications.As such, many Presto Geospatial functions require, or more accurately, assume thatgeometries that are operated on are both simple and valid. For example, it does notmake sense to calculate the area of a polygon that has a hole defined outside of thepolygon, or to construct a polygon from a non-simple boundary line.

Presto Geospatial functions support the Well-Known Text (WKT) form of spatial objects:

POINT (0 0)
LINESTRING (0 0, 1 1, 1 2)
POLYGON ((0 0, 4 0, 4 4, 0 4, 0 0), (1 1, 2 1, 2 2, 1 2, 1 1))
MULTIPOINT (0 0, 1 2)
MULTILINESTRING ((0 0, 1 1, 1 2), (2 3, 3 2, 5 4))
MULTIPOLYGON (((0 0, 4 0, 4 4, 0 4, 0 0), (1 1, 2 1, 2 2, 1 2, 1 1)), ((-1 -1, -1 -2, -2 -2, -2 -1, -1 -1)))
GEOMETRYCOLLECTION (POINT(2 3), LINESTRING (2 3, 3 4))

Constructors

STPoint(_double, double) → Point: Returns a geometry type point object with the given coordinate values.

STLineFromText(_varchar) → LineString: Returns a geometry type linestring object from WKT representation.

STPolygon(_varchar) → Polygon: Returns a geometry type polygon object from WKT representation.

STGeometryFromText(_varchar) → Geometry: Returns a geometry type object from WKT representation.

STAsText(_Geometry) → varchar: Returns the WKT representation of the geometry. For empty geometries,ST_AsText(ST_LineFromText('LINESTRING EMPTY')) will produce 'MULTILINESTRING EMPTY'and ST_AsText(ST_Polygon('POLYGON EMPTY')) will produce 'MULTIPOLYGON EMPTY'.

Relationship Tests

STContains(_Geometry, Geometry) → boolean: Returns true if and only if no points of the second geometry lie in the exteriorof the first geometry, and at least one point of the interior of the first geometrylies in the interior of the second geometry.

STCrosses(_Geometry, Geometry) → boolean: Returns true if the supplied geometries have some, but not all, interior points in common.

STDisjoint(_Geometry, Geometry) → boolean: Returns true if the give geometries do not spatially intersect –if they do not share any space together.

STEquals(_Geometry, Geometry) → boolean: Returns true if the given geometries represent the same geometry.

STIntersects(_Geometry, Geometry) → boolean: Returns true if the given geometries spatially intersect in two dimensions(share any portion of space) and false if they don not (they are disjoint).

STOverlaps(_Geometry, Geometry) → boolean: Returns true if the given geometries share space, are of the same dimension,but are not completely contained by each other.

STRelate(_Geometry, Geometry) → boolean: Returns true if first geometry is spatially related to second geometry.

STTouches(_Geometry, Geometry) → boolean: Returns true if the given geometries have at least one point in common,but their interiors do not intersect.

STWithin(_Geometry, Geometry) → boolean: Returns true if first geometry is completely inside second geometry.

Operations

STBoundary(_Geometry) → Geometry: Returns the closure of the combinatorial boundary of this geometry.

STBuffer(_Geometry, distance) → Geometry: Returns the geometry that represents all points whose distance from the specified geometryis less than or equal to the specified distance.

STDifference(_Geometry, Geometry) → Geometry: Returns the geometry value that represents the point set difference of the given geometries.

STEnvelope(_Geometry) → Geometry: Returns the bounding rectangular polygon of a geometry.

STEnvelopeAsPts(_Geometry) → Geometry: Returns an array of two points: the lower left and upper right corners of the boundingrectangular polygon of a geometry. Returns null if input geometry is empty.

STExteriorRing(_Geometry) → Geometry: Returns a line string representing the exterior ring of the input polygon.

STIntersection(_Geometry, Geometry) → Geometry: Returns the geometry value that represents the point set intersection of two geometries.

STSymDifference(_Geometry, Geometry) → Geometry: Returns the geometry value that represents the point set symmetric difference of two geometries.

STUnion(_Geometry, Geometry) → Geometry: Returns a geometry that represents the point set union of the input geometries.

This function doesn’t support geometry collections.

Accessors

STArea(_Geometry) → double: Returns the 2D Euclidean area of a geometry.

For Point and LineString types, returns 0.0.For GeometryCollection types, returns the sum of the areas of the individualgeometries.

STCentroid(_Geometry) → Geometry: Returns the point value that is the mathematical centroid of a geometry.

STConvexHull(_Geometry) → Geometry: Returns the minimum convex geometry that encloses all input geometries.This function doesn’t support geometry collections.

STCoordDim(_Geometry) → bigint: Return the coordinate dimension of the geometry.

STDimension(_Geometry) → bigint: Returns the inherent dimension of this geometry object, which must beless than or equal to the coordinate dimension.

STDistance(_Geometry, Geometry) → double: Returns the 2-dimensional cartesian minimum distance (based on spatial ref)between two geometries in projected units.

STGeometryN(_Geometry, index) → Geometry: Returns the geometry element at a given index (indices start at 1).If the geometry is a collection of geometries (e.g., GEOMETRYCOLLECTION or MULTI),returns the geometry at a given index.If the given index is less than 1 or greater than the total number of elements in the collection,returns NULL.Use :func:STNumGeometries to find out the total number of elements.Singular geometries (e.g., POINT, LINESTRING, POLYGON), are treated as collections of one element.Empty geometries are treated as empty collections.

ST_InteriorRingN(_Geometry, index) → Geometry: Returns the interior ring element at the specified index (indices start at 1). Ifthe given index is less than 1 or greater than the total number of interior ringsin the input geometry, returns NULL. Throws an error if the input geometry isnot a polygon.Use :func:STNumInteriorRing to find out the total number of elements.

ST_GeometryType(_Geometry) → varchar: Returns the type of the geometry.

STIsClosed(_Geometry) → boolean: Returns true if the linestring’s start and end points are coincident.

STIsEmpty(_Geometry) → boolean: Returns true if this Geometry is an empty geometrycollection, polygon, point etc.

STIsSimple(_Geometry) → boolean: Returns true if this Geometry has no anomalous geometric points, such as self intersection or self tangency.

STIsRing(_Geometry) → boolean: Returns true if and only if the line is closed and simple.

STIsValid(_Geometry) → boolean: Returns true if and only if the input geometry is well formed.Use geometry_invalid_reason() to determine why the geometry is not well formed.

STLength(_Geometry) → double: Returns the length of a linestring or multi-linestring using Euclidean measurement on atwo dimensional plane (based on spatial ref) in projected units.

STPointN(_LineString, index) → Point: Returns the vertex of a linestring at a given index (indices start at 1).If the given index is less than 1 or greater than the total number of elements in the collection,returns NULL.Use :func:STNumPoints to find out the total number of elements.

ST_XMax(_Geometry) → double: Returns X maxima of a bounding box of a geometry.

STYMax(_Geometry) → double: Returns Y maxima of a bounding box of a geometry.

STXMin(_Geometry) → double: Returns X minima of a bounding box of a geometry.

STYMin(_Geometry) → double: Returns Y minima of a bounding box of a geometry.

STStartPoint(_Geometry) → point: Returns the first point of a LineString geometry as a Point.This is a shortcut for STPointN(geometry, 1).

simplify_geometry(_Geometry, double) → Geometry: Returns a “simplified” version of the input geometry using the Douglas-Peucker algorithm.Will avoid creating derived geometries (polygons in particular) that are invalid.

STEndPoint(_Geometry) → point: Returns the last point of a LineString geometry as a Point.This is a shortcut for STPointN(geometry, ST_NumPoints(geometry)).

ST_X(_Point) → double: Return the X coordinate of the point.

STY(_Point) → double: Return the Y coordinate of the point.

STInteriorRings(_Geometry) → Geometry: Returns an array of all interior rings found in the input geometry, or an emptyarray if the polygon has no interior rings. Returns null if the input geometryis empty. Throws an error if the input geometry is not a polygon.

STNumGeometries(_Geometry) → bigint: Returns the number of geometries in the collection.If the geometry is a collection of geometries (e.g., GEOMETRYCOLLECTION or MULTI),returns the number of geometries,for single geometries returns 1,for empty geometries returns 0.

STGeometries(_Geometry) → Geometry: Returns an array of geometries in the specified collection. Returns a one-element arrayif the input geometry is not a multi-geometry. Returns null if input geometry is empty.

STNumPoints(_Geometry) → bigint: Returns the number of points in a geometry. This is an extension to the SQL/MMSTNumPoints function which only applies to point and linestring.

ST_NumInteriorRing(_Geometry) → bigint: Returns the cardinality of the collection of interior rings of a polygon.

linelocate_point(_LineString, Point) → double: Returns a float between 0 and 1 representing the location of the closest point onthe LineString to the given Point, as a fraction of total 2d line length.

Returns null if a LineString or a Point is empty or null.

geometryinvalid_reason(_Geometry) → varchar: Returns the reason for why the input geometry is not valid.Returns null if the input is valid.

greatcircle_distance(_latitude1, longitude1, latitude2, longitude2) → double: Returns the great-circle distance between two points on Earth’s surface in kilometers.

Bing Tiles

These functions convert between geometries andBing tiles.

bingtile(_x, y, zoom_level) → BingTile: Creates a Bing tile object from XY coordinates and a zoom level.Zoom levels from 1 to 23 are supported.

bingtile(_quadKey) → BingTile: Creates a Bing tile object from a quadkey.

bingtile_at(_latitude, longitude, zoom_level) → BingTile: Returns a Bing tile at a given zoom level containing a point at a given latitudeand longitude. Latitude must be within [-85.05112878, 85.05112878] range.Longitude must be within [-180, 180] range. Zoom levels from 1 to 23 are supported.

bingtiles_around(_latitude, longitude, zoom_level) → array<BingTile>: Returns a collection of Bing tiles that surround the point specifiedby the latitude and longitude arguments at a given zoom level.

bingtile_coordinates(_tile) → row<x, y>: Returns the XY coordinates of a given Bing tile.

bingtile_polygon(_tile) → Geometry: Returns the polygon representation of a given Bing tile.

bingtile_quadkey(_tile) → varchar: Returns the quadkey of a given Bing tile.

bingtile_zoom_level(_tile) → tinyint: Returns the zoom level of a given Bing tile.

geometryto_bing_tiles(_geometry, zoom_level) → array<BingTile>: Returns the minimum set of Bing tiles that fully covers a given geometry ata given zoom level. Zoom levels from 1 to 23 are supported.

原文: https://prestodb.io/docs/current/functions/geospatial.html