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DuckDB Spatial Function Reference

Function Index

Scalar Functions

Function Summary
ST_Area Compute the area of a geometry.
ST_Area_Spheroid Returns the area of a geometry in meters, using an ellipsoidal model of the earth
ST_AsGeoJSON Returns the geometry as a GeoJSON fragment
ST_AsHEXWKB Returns the geometry as a HEXWKB string
ST_AsSVG Convert the geometry into a SVG fragment or path
ST_AsText Returns the geometry as a WKT string
ST_AsWKB Returns the geometry as a WKB blob
ST_Boundary Returns the "boundary" of a geometry
ST_Buffer Returns a buffer around the input geometry at the target distance
ST_Centroid Calculates the centroid of a geometry
ST_Collect Collects a list of geometries into a collection geometry.
ST_CollectionExtract Extracts geometries from a GeometryCollection into a typed multi geometry.
ST_Contains Returns true if geom1 contains geom2.
ST_ContainsProperly Returns true if geom1 "properly contains" geom2
ST_ConvexHull Returns the convex hull enclosing the geometry
ST_CoveredBy Returns true if geom1 is "covered" by geom2
ST_Covers Returns if geom1 "covers" geom2
ST_Crosses Returns true if geom1 "crosses" geom2
ST_DWithin Returns if two geometries are within a target distance of each-other
ST_DWithin_Spheroid Returns if two POINT_2D's are within a target distance in meters, using an ellipsoidal model of the earths surface
ST_Difference Returns the "difference" between two geometries
ST_Dimension Returns the dimension of a geometry.
ST_Disjoint Returns if two geometries are disjoint
ST_Distance Returns the distance between two geometries.
ST_Distance_Sphere Returns the haversine distance between two geometries.
ST_Distance_Spheroid Returns the distance between two geometries in meters using a ellipsoidal model of the earths surface
ST_Dump Dumps a geometry into a list of sub-geometries and their "path" in the original geometry.
ST_EndPoint Returns the last point of a line.
ST_Envelope Returns the minimum bounding box for the input geometry as a polygon geometry.
ST_Equals Compares two geometries for equality
ST_Extent Returns the minimal bounding box enclosing the input geometry
ST_ExteriorRing Returns the exterior ring (shell) of a polygon geometry.
ST_FlipCoordinates Returns a new geometry with the coordinates of the input geometry "flipped" so that x = y and y = x.
ST_Force2D Forces the vertices of a geometry to have X and Y components
ST_Force3DM Forces the vertices of a geometry to have X, Y and M components
ST_Force3DZ Forces the vertices of a geometry to have X, Y and Z components
ST_Force4D Forces the vertices of a geometry to have X, Y, Z and M components
ST_GeomFromGeoJSON Deserializes a GEOMETRY from a GeoJSON fragment.
ST_GeomFromHEXEWKB Deserialize a GEOMETRY from a HEXEWKB encoded string
ST_GeomFromHEXWKB Creates a GEOMETRY from a HEXWKB string
ST_GeomFromText Deserializes a GEOMETRY from a WKT string, optionally ignoring invalid geometries
ST_GeomFromWKB Deserializes a GEOMETRY from a WKB encoded blob
ST_GeometryType Returns a 'GEOMETRY_TYPE' enum identifying the input geometry type. Possible enum return types are: POINT, LINESTRING, POLYGON, MULTIPOINT, MULTILINESTRING, MULTIPOLYGON, and GEOMETRYCOLLECTION.
ST_HasM Check if the input geometry has M values.
ST_HasZ Check if the input geometry has Z values.
ST_Hilbert Encodes the X and Y values as the hilbert curve index for a curve covering the given bounding box.
ST_Intersection Returns the "intersection" of geom1 and geom2
ST_Intersects Returns true if two geometries intersects
ST_Intersects_Extent Returns true if the extent of two geometries intersects
ST_IsClosed Returns true if a geometry is "closed"
ST_IsEmpty Returns true if the geometry is "empty"
ST_IsRing Returns true if the input line geometry is a ring (both ST_IsClosed and ST_IsSimple).
ST_IsSimple Returns true if the input geometry is "simple"
ST_IsValid Returns true if the geometry is topologically "valid"
ST_Length Returns the length of the input line geometry
ST_Length_Spheroid Returns the length of the input geometry in meters, using a ellipsoidal model of the earth
ST_LineMerge "Merges" the input line geometry, optionally taking direction into account.
ST_M Returns the M value of a point geometry, or NULL if not a point or empty
ST_MMax Returns the maximum M value of a geometry
ST_MMin Returns the minimum M value of a geometry
ST_MakeEnvelope Returns a minimal bounding box polygon enclosing the input geometry
ST_MakeLine Creates a LINESTRING geometry from a pair or list of input points
ST_MakePolygon Creates a polygon from a shell geometry and an optional set of holes
ST_MakeValid Attempts to make an invalid geometry valid without removing any vertices
ST_Multi Turns a single geometry into a multi geometry.
ST_NGeometries Returns the number of component geometries in a collection geometry.
ST_NInteriorRings Returns the number if interior rings of a polygon
ST_NPoints Returns the number of vertices within a geometry
ST_Normalize Returns a "normalized" version of the input geometry.
ST_NumGeometries Returns the number of component geometries in a collection geometry.
ST_NumInteriorRings Returns the number if interior rings of a polygon
ST_NumPoints Returns the number of vertices within a geometry
ST_Overlaps Returns true if geom1 "overlaps" geom2
ST_Perimeter Returns the length of the perimeter of the geometry
ST_Perimeter_Spheroid Returns the length of the perimeter in meters using an ellipsoidal model of the earths surface
ST_Point Creates a GEOMETRY point
ST_Point2D Creates a POINT_2D
ST_Point3D Creates a POINT_3D
ST_Point4D Creates a POINT_4D
ST_PointN Returns the n'th vertex from the input geometry as a point geometry
ST_PointOnSurface Returns a point that is guaranteed to be on the surface of the input geometry. Sometimes a useful alternative to ST_Centroid.
ST_Points Collects all the vertices in the geometry into a multipoint
ST_QuadKey Compute the quadkey for a given lon/lat point at a given level.
ST_ReducePrecision Returns the geometry with all vertices reduced to the target precision
ST_RemoveRepeatedPoints Returns a new geometry with repeated points removed, optionally within a target distance of eachother.
ST_Reverse Returns a new version of the input geometry with the order of its vertices reversed
ST_ShortestLine Returns the line between the two closest points between geom1 and geom2
ST_Simplify Simplifies the input geometry by collapsing edges smaller than 'distance'
ST_SimplifyPreserveTopology Returns a simplified geometry but avoids creating invalid topologies
ST_StartPoint Returns the first point of a line geometry
ST_Touches Returns true if geom1 "touches" geom2
ST_Transform Transforms a geometry between two coordinate systems
ST_Union Returns the union of two geometries.
ST_Within Returns true if geom1 is "within" geom2
ST_X Returns the X value of a point geometry, or NULL if not a point or empty
ST_XMax Returns the maximum X value of a geometry
ST_XMin Returns the minimum X value of a geometry
ST_Y Returns the Y value of a point geometry, or NULL if not a point or empty
ST_YMax Returns the maximum Y value of a geometry
ST_YMin Returns the minimum Y value of a geometry
ST_Z Returns the Z value of a point geometry, or NULL if not a point or empty
ST_ZMFlag Returns a flag indicating the presence of Z and M values in the input geometry.
ST_ZMax Returns the maximum Z value of a geometry
ST_ZMin Returns the minimum Z value of a geometry

Aggregate Functions

Function Summary
ST_Envelope_Agg Alias for ST_Extent_Agg.
ST_Extent_Agg Computes the minimal-bounding-box polygon containing the set of input geometries
ST_Intersection_Agg Computes the intersection of a set of geometries
ST_Union_Agg Computes the union of a set of input geometries

Table Functions

Function Summary
ST_Drivers Returns the list of supported GDAL drivers and file formats
ST_Read Read and import a variety of geospatial file formats using the GDAL library.
ST_ReadOSM The ST_ReadOsm() table function enables reading compressed OpenStreetMap data directly from a .osm.pbf file.
ST_Read_Meta Read the metadata from a variety of geospatial file formats using the GDAL library.

Scalar Functions

ST_Area

Signatures

DOUBLE ST_Area (col0 POINT_2D)
DOUBLE ST_Area (col0 LINESTRING_2D)
DOUBLE ST_Area (col0 POLYGON_2D)
DOUBLE ST_Area (col0 GEOMETRY)
DOUBLE ST_Area (col0 BOX_2D)

Description

Compute the area of a geometry.

Returns 0.0 for any geometry that is not a POLYGON, MULTIPOLYGON or GEOMETRYCOLLECTION containing polygon geometries. The area is in the same units as the spatial reference system of the geometry.

The POINT_2D and LINESTRING_2D overloads of this function always return 0.0 but are included for completeness.

Example

select ST_Area('POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))'::geometry);
	-- 1.0

ST_Area_Spheroid

Signatures

DOUBLE ST_Area_Spheroid (col0 POLYGON_2D)
DOUBLE ST_Area_Spheroid (col0 GEOMETRY)

Description

Returns the area of a geometry in meters, using an ellipsoidal model of the earth

The input geometry is assumed to be in the EPSG:4326 coordinate system (WGS84), with [latitude, longitude] axis order and the area is returned in square meters. This function uses the GeographicLib library, calculating the area using an ellipsoidal model of the earth. This is a highly accurate method for calculating the area of a polygon taking the curvature of the earth into account, but is also the slowest.

Returns 0.0 for any geometry that is not a POLYGON, MULTIPOLYGON or GEOMETRYCOLLECTION containing polygon geometries.

ST_AsGeoJSON

Signature

JSON ST_AsGeoJSON (col0 GEOMETRY)

Description

Returns the geometry as a GeoJSON fragment

This does not return a complete GeoJSON document, only the geometry fragment. To construct a complete GeoJSON document or feature, look into using the DuckDB JSON extension in conjunction with this function. This function supports geometries with Z values, but not M values.

Example

select ST_AsGeoJSON('POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))'::geometry);
----
{"type":"Polygon","coordinates":[[[0.0,0.0],[0.0,1.0],[1.0,1.0],[1.0,0.0],[0.0,0.0]]]}

-- Convert a geometry into a full GeoJSON feature (requires the JSON extension to be loaded)
SELECT CAST({
	type: 'Feature', 
	geometry: ST_AsGeoJSON(ST_Point(1,2)), 
	properties: { 
		name: 'my_point' 
	} 
} AS JSON);
----
{"type":"Feature","geometry":{"type":"Point","coordinates":[1.0,2.0]},"properties":{"name":"my_point"}}

ST_AsHEXWKB

Signature

VARCHAR ST_AsHEXWKB (col0 GEOMETRY)

Description

Returns the geometry as a HEXWKB string

Example

SELECT ST_AsHexWKB('POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))'::geometry);
----
01030000000100000005000000000000000000000000000...

ST_AsSVG

Signature

VARCHAR ST_AsSVG (col0 GEOMETRY, col1 BOOLEAN, col2 INTEGER)

Description

Convert the geometry into a SVG fragment or path

Convert the geometry into a SVG fragment or path The SVG fragment is returned as a string. The fragment is a path element that can be used in an SVG document. The second boolean argument specifies whether the path should be relative or absolute. The third argument specifies the maximum number of digits to use for the coordinates.

Points are formatted as cx/cy using absolute coordinates or x/y using relative coordinates.

Example

SELECT ST_AsSVG('POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))'::GEOMETRY, false, 15);
----
M 0 0 L 0 -1 1 -1 1 0 Z

ST_AsText

Signatures

VARCHAR ST_AsText (col0 POINT_2D)
VARCHAR ST_AsText (col0 LINESTRING_2D)
VARCHAR ST_AsText (col0 POLYGON_2D)
VARCHAR ST_AsText (col0 BOX_2D)
VARCHAR ST_AsText (col0 GEOMETRY)

Description

Returns the geometry as a WKT string

Example

SELECT ST_AsText(ST_MakeEnvelope(0,0,1,1));
----
POLYGON ((0 0, 0 1, 1 1, 1 0, 0 0))

ST_AsWKB

Signature

WKB_BLOB ST_AsWKB (col0 GEOMETRY)

Description

Returns the geometry as a WKB blob

Example

SELECT ST_AsWKB('POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))'::GEOMETRY)::BLOB;
----
\x01\x03\x00\x00\x00\x01\x00\x00\x00\x05...

ST_Boundary

Signature

GEOMETRY ST_Boundary (col0 GEOMETRY)

Description

Returns the "boundary" of a geometry

ST_Buffer

Signatures

GEOMETRY ST_Buffer (geom GEOMETRY, distance DOUBLE)
GEOMETRY ST_Buffer (geom GEOMETRY, distance DOUBLE, num_triangles INTEGER)
GEOMETRY ST_Buffer (geom GEOMETRY, distance DOUBLE, num_triangles INTEGER, join_style VARCHAR, cap_style VARCHAR, mitre_limit DOUBLE)

Description

Returns a buffer around the input geometry at the target distance

geom is the input geometry.

distance is the target distance for the buffer, using the same units as the input geometry.

num_triangles represents how many triangles that will be produced to approximate a quarter circle. The larger the number, the smoother the resulting geometry. The default value is 8.

join_style must be one of "JOIN_ROUND", "JOIN_MITRE", "JOIN_BEVEL". This parameter is case-insensitive.

cap_style must be one of "CAP_ROUND", "CAP_FLAT", "CAP_SQUARE". This parameter is case-insensitive.

mitre_limit only applies when join_style is "JOIN_MITRE". It is the ratio of the distance from the corner to the mitre point to the corner radius. The default value is 1.0.

This is a planar operation and will not take into account the curvature of the earth.

ST_Centroid

Signatures

POINT_2D ST_Centroid (col0 POINT_2D)
POINT_2D ST_Centroid (col0 LINESTRING_2D)
POINT_2D ST_Centroid (col0 POLYGON_2D)
POINT_2D ST_Centroid (col0 BOX_2D)
POINT_2D ST_Centroid (col0 BOX_2DF)
GEOMETRY ST_Centroid (col0 GEOMETRY)

Description

Calculates the centroid of a geometry

Example

select st_centroid('POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))'::geometry);
----
 POINT(0.5 0.5)

ST_Collect

Signature

GEOMETRY ST_Collect (col0 GEOMETRY[])

Description

Collects a list of geometries into a collection geometry.

  • If all geometries are POINT's, a MULTIPOINT is returned.
  • If all geometries are LINESTRING's, a MULTILINESTRING is returned.
  • If all geometries are POLYGON's, a MULTIPOLYGON is returned.
  • Otherwise if the input collection contains a mix of geometry types, a GEOMETRYCOLLECTION is returned.

Empty and NULL geometries are ignored. If all geometries are empty or NULL, a GEOMETRYCOLLECTION EMPTY is returned.

Example

-- With all POINT's, a MULTIPOINT is returned
SELECT ST_Collect([ST_Point(1, 2), ST_Point(3, 4)]);
----
MULTIPOINT (1 2, 3 4)

-- With mixed geometry types, a GEOMETRYCOLLECTION is returned
SELECT ST_Collect([ST_Point(1, 2), ST_GeomFromText('LINESTRING(3 4, 5 6)')]);
----
GEOMETRYCOLLECTION (POINT (1 2), LINESTRING (3 4, 5 6))

-- Note that the empty geometry is ignored, so the result is a MULTIPOINT
SELECT ST_Collect([ST_Point(1, 2), NULL, ST_GeomFromText('GEOMETRYCOLLECTION EMPTY')]);
----
MULTIPOINT (1 2)

-- If all geometries are empty or NULL, a GEOMETRYCOLLECTION EMPTY is returned
SELECT ST_Collect([NULL, ST_GeomFromText('GEOMETRYCOLLECTION EMPTY')]);
----
GEOMETRYCOLLECTION EMPTY

-- Tip: You can use the `ST_Collect` function together with the `list()` aggregate function to collect multiple rows of geometries into a single geometry collection:

CREATE TABLE points (geom GEOMETRY);

INSERT INTO points VALUES (ST_Point(1, 2)), (ST_Point(3, 4));

SELECT ST_Collect(list(geom)) FROM points;
----
MULTIPOINT (1 2, 3 4)

ST_CollectionExtract

Signatures

GEOMETRY ST_CollectionExtract (geom GEOMETRY)
GEOMETRY ST_CollectionExtract (geom GEOMETRY, type INTEGER)

Description

Extracts geometries from a GeometryCollection into a typed multi geometry.

If the input geometry is a GeometryCollection, the function will return a multi geometry, determined by the type parameter.

  • if type = 1, returns a MultiPoint containg all the Points in the collection
  • if type = 2, returns a MultiLineString containg all the LineStrings in the collection
  • if type = 3, returns a MultiPolygon containg all the Polygons in the collection

If no type parameters is provided, the function will return a multi geometry matching the highest "surface dimension" of the contained geometries. E.g. if the collection contains only Points, a MultiPoint will be returned. But if the collection contains both Points and LineStrings, a MultiLineString will be returned. Similarly, if the collection contains Polygons, a MultiPolygon will be returned. Contained geometries of a lower surface dimension will be ignored.

If the input geometry contains nested GeometryCollections, their geometries will be extracted recursively and included into the final multi geometry as well.

If the input geometry is not a GeometryCollection, the function will return the input geometry as is.

Example

select st_collectionextract('MULTIPOINT(1 2,3 4)'::geometry, 1);
-- MULTIPOINT (1 2, 3 4)

ST_Contains

Signatures

BOOLEAN ST_Contains (geom1 POLYGON_2D, geom2 POINT_2D)
BOOLEAN ST_Contains (geom1 GEOMETRY, geom2 GEOMETRY)

Description

Returns true if geom1 contains geom2.

Example

select st_contains('POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))'::geometry, 'POINT(0.5 0.5)'::geometry);
----
true

ST_ContainsProperly

Signature

BOOLEAN ST_ContainsProperly (geom1 GEOMETRY, geom2 GEOMETRY)

Description

Returns true if geom1 "properly contains" geom2

ST_ConvexHull

Signature

GEOMETRY ST_ConvexHull (col0 GEOMETRY)

Description

Returns the convex hull enclosing the geometry

ST_CoveredBy

Signature

BOOLEAN ST_CoveredBy (geom1 GEOMETRY, geom2 GEOMETRY)

Description

Returns true if geom1 is "covered" by geom2

ST_Covers

Signature

BOOLEAN ST_Covers (geom1 GEOMETRY, geom2 GEOMETRY)

Description

Returns if geom1 "covers" geom2

ST_Crosses

Signature

BOOLEAN ST_Crosses (geom1 GEOMETRY, geom2 GEOMETRY)

Description

Returns true if geom1 "crosses" geom2

ST_DWithin

Signature

BOOLEAN ST_DWithin (col0 GEOMETRY, col1 GEOMETRY, col2 DOUBLE)

Description

Returns if two geometries are within a target distance of each-other

ST_DWithin_Spheroid

Signature

BOOLEAN ST_DWithin_Spheroid (col0 POINT_2D, col1 POINT_2D, col2 DOUBLE)

Description

Returns if two POINT_2D's are within a target distance in meters, using an ellipsoidal model of the earths surface

The input geometry is assumed to be in the [EPSG:4326](https://en.wikipedia.org/wiki/World_Geodetic_System) coordinate system (WGS84), with [latitude, longitude] axis order and the distance is returned in meters. This function uses the [GeographicLib](https://geographiclib.sourceforge.io/) library to solve the [inverse geodesic problem](https://en.wikipedia.org/wiki/Geodesics_on_an_ellipsoid#Solution_of_the_direct_and_inverse_problems), calculating the distance between two points using an ellipsoidal model of the earth. This is a highly accurate method for calculating the distance between two arbitrary points taking the curvature of the earths surface into account, but is also the slowest.

ST_Difference

Signature

GEOMETRY ST_Difference (col0 GEOMETRY, col1 GEOMETRY)

Description

Returns the "difference" between two geometries

ST_Dimension

Signature

INTEGER ST_Dimension (col0 GEOMETRY)

Description

Returns the dimension of a geometry.

Example

select st_dimension('POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))'::geometry);
----
2

ST_Disjoint

Signature

BOOLEAN ST_Disjoint (col0 GEOMETRY, col1 GEOMETRY)

Description

Returns if two geometries are disjoint

ST_Distance

Signatures

DOUBLE ST_Distance (col0 POINT_2D, col1 POINT_2D)
DOUBLE ST_Distance (col0 POINT_2D, col1 LINESTRING_2D)
DOUBLE ST_Distance (col0 LINESTRING_2D, col1 POINT_2D)
DOUBLE ST_Distance (col0 GEOMETRY, col1 GEOMETRY)

Description

Returns the distance between two geometries.

Example

select st_distance('POINT(0 0)'::geometry, 'POINT(1 1)'::geometry);
----
1.4142135623731

ST_Distance_Sphere

Signatures

DOUBLE ST_Distance_Sphere (col0 POINT_2D, col1 POINT_2D)
DOUBLE ST_Distance_Sphere (col0 GEOMETRY, col1 GEOMETRY)

Description

Returns the haversine distance between two geometries.

  • Only supports POINT geometries.
  • Returns the distance in meters.
  • The input is expected to be in WGS84 (EPSG:4326) coordinates, using a [latitude, longitude] axis order.

ST_Distance_Spheroid

Signature

DOUBLE ST_Distance_Spheroid (col0 POINT_2D, col1 POINT_2D)

Description

Returns the distance between two geometries in meters using a ellipsoidal model of the earths surface

The input geometry is assumed to be in the EPSG:4326 coordinate system (WGS84), with [latitude, longitude] axis order and the distance limit is expected to be in meters. This function uses the GeographicLib library to solve the inverse geodesic problem, calculating the distance between two points using an ellipsoidal model of the earth. This is a highly accurate method for calculating the distance between two arbitrary points taking the curvature of the earths surface into account, but is also the slowest.

Example

-- Note: the coordinates are in WGS84 and [latitude, longitude] axis order
-- Whats the distance between New York and Amsterdam (JFK and AMS airport)?
SELECT st_distance_spheroid(
st_point(40.6446, -73.7797),
st_point(52.3130, 4.7725)
);
----
5863418.7459356235
-- Roughly 5863km!

ST_Dump

Signature

STRUCT(geom GEOMETRY, path INTEGER[])[] ST_Dump (col0 GEOMETRY)

Description

Dumps a geometry into a list of sub-geometries and their "path" in the original geometry.

Example

select st_dump('MULTIPOINT(1 2,3 4)'::geometry);
----
[{'geom': 'POINT(1 2)', 'path': [0]}, {'geom': 'POINT(3 4)', 'path': [1]}]

ST_EndPoint

Signatures

GEOMETRY ST_EndPoint (col0 GEOMETRY)
POINT_2D ST_EndPoint (col0 LINESTRING_2D)

Description

Returns the last point of a line.

Example

select ST_EndPoint('LINESTRING(0 0, 1 1)'::geometry);
-- POINT(1 1)

ST_Envelope

Signature

GEOMETRY ST_Envelope (col0 GEOMETRY)

Description

Returns the minimum bounding box for the input geometry as a polygon geometry.

ST_Equals

Signature

BOOLEAN ST_Equals (col0 GEOMETRY, col1 GEOMETRY)

Description

Compares two geometries for equality

ST_Extent

Signatures

BOX_2D ST_Extent (col0 GEOMETRY)
BOX_2D ST_Extent (col0 WKB_BLOB)

Description

Returns the minimal bounding box enclosing the input geometry

ST_ExteriorRing

Signatures

LINESTRING_2D ST_ExteriorRing (col0 POLYGON_2D)
GEOMETRY ST_ExteriorRing (col0 GEOMETRY)

Description

Returns the exterior ring (shell) of a polygon geometry.

ST_FlipCoordinates

Signatures

POINT_2D ST_FlipCoordinates (col0 POINT_2D)
LINESTRING_2D ST_FlipCoordinates (col0 LINESTRING_2D)
POLYGON_2D ST_FlipCoordinates (col0 POLYGON_2D)
BOX_2D ST_FlipCoordinates (col0 BOX_2D)
GEOMETRY ST_FlipCoordinates (col0 GEOMETRY)

Description

Returns a new geometry with the coordinates of the input geometry "flipped" so that x = y and y = x.

ST_Force2D

Signature

GEOMETRY ST_Force2D (col0 GEOMETRY)

Description

Forces the vertices of a geometry to have X and Y components

This function will drop any Z and M values from the input geometry, if present. If the input geometry is already 2D, it will be returned as is.

ST_Force3DM

Signature

GEOMETRY ST_Force3DM (col0 GEOMETRY, col1 DOUBLE)

Description

Forces the vertices of a geometry to have X, Y and M components

The following cases apply:

  • If the input geometry has a Z component but no M component, the Z component will be replaced with the new M value.
  • If the input geometry has a M component but no Z component, it will be returned as is.
  • If the input geometry has both a Z component and a M component, the Z component will be removed.
  • Otherwise, if the input geometry has neither a Z or M component, the new M value will be added to the vertices of the input geometry.

ST_Force3DZ

Signature

GEOMETRY ST_Force3DZ (col0 GEOMETRY, col1 DOUBLE)

Description

Forces the vertices of a geometry to have X, Y and Z components

The following cases apply:

  • If the input geometry has a M component but no Z component, the M component will be replaced with the new Z value.
  • If the input geometry has a Z component but no M component, it will be returned as is.
  • If the input geometry has both a Z component and a M component, the M component will be removed.
  • Otherwise, if the input geometry has neither a Z or M component, the new Z value will be added to the vertices of the input geometry.

ST_Force4D

Signature

GEOMETRY ST_Force4D (col0 GEOMETRY, col1 DOUBLE, col2 DOUBLE)

Description

Forces the vertices of a geometry to have X, Y, Z and M components

The following cases apply:

  • If the input geometry has a Z component but no M component, the new M value will be added to the vertices of the input geometry.
  • If the input geometry has a M component but no Z component, the new Z value will be added to the vertices of the input geometry.
  • If the input geometry has both a Z component and a M component, the geometry will be returned as is.
  • Otherwise, if the input geometry has neither a Z or M component, the new Z and M values will be added to the vertices of the input geometry.

ST_GeomFromGeoJSON

Signatures

GEOMETRY ST_GeomFromGeoJSON (col0 VARCHAR)
GEOMETRY ST_GeomFromGeoJSON (col0 JSON)

Description

Deserializes a GEOMETRY from a GeoJSON fragment.

Example

SELECT ST_GeomFromGeoJSON('{"type":"Point","coordinates":[1.0,2.0]}');
----
POINT (1 2)

ST_GeomFromHEXEWKB

Signature

GEOMETRY ST_GeomFromHEXEWKB (col0 VARCHAR)

Description

Deserialize a GEOMETRY from a HEXEWKB encoded string

ST_GeomFromHEXWKB

Signature

GEOMETRY ST_GeomFromHEXWKB (col0 VARCHAR)

Description

Creates a GEOMETRY from a HEXWKB string

ST_GeomFromText

Signatures

GEOMETRY ST_GeomFromText (col0 VARCHAR)
GEOMETRY ST_GeomFromText (col0 VARCHAR, col1 BOOLEAN)

Description

Deserializes a GEOMETRY from a WKT string, optionally ignoring invalid geometries

ST_GeomFromWKB

Signatures

GEOMETRY ST_GeomFromWKB (col0 WKB_BLOB)
GEOMETRY ST_GeomFromWKB (col0 BLOB)

Description

Deserializes a GEOMETRY from a WKB encoded blob

ST_GeometryType

Signatures

ANY ST_GeometryType (col0 POINT_2D)
ANY ST_GeometryType (col0 LINESTRING_2D)
ANY ST_GeometryType (col0 POLYGON_2D)
ANY ST_GeometryType (col0 GEOMETRY)
ANY ST_GeometryType (col0 WKB_BLOB)

Description

Returns a 'GEOMETRY_TYPE' enum identifying the input geometry type. Possible enum return types are: POINT, LINESTRING, POLYGON, MULTIPOINT, MULTILINESTRING, MULTIPOLYGON, and GEOMETRYCOLLECTION.

Example

SELECT DISTINCT ST_GeometryType(ST_GeomFromText('POINT(1 1)'));
----
POINT

ST_HasM

Signatures

BOOLEAN ST_HasM (col0 GEOMETRY)
BOOLEAN ST_HasM (col0 WKB_BLOB)

Description

Check if the input geometry has M values.

Example

-- HasM for a 2D geometry
SELECT ST_HasM(ST_GeomFromText('POINT(1 1)'));
----
false

-- HasM for a 3DZ geometry
SELECT ST_HasM(ST_GeomFromText('POINT Z(1 1 1)'));
----
false

-- HasM for a 3DM geometry
SELECT ST_HasM(ST_GeomFromText('POINT M(1 1 1)'));
----
true

-- HasM for a 4D geometry
SELECT ST_HasM(ST_GeomFromText('POINT ZM(1 1 1 1)'));
----
true

ST_HasZ

Signatures

BOOLEAN ST_HasZ (col0 GEOMETRY)
BOOLEAN ST_HasZ (col0 WKB_BLOB)

Description

Check if the input geometry has Z values.

Example

-- HasZ for a 2D geometry
SELECT ST_HasZ(ST_GeomFromText('POINT(1 1)'));
----
false

-- HasZ for a 3DZ geometry
SELECT ST_HasZ(ST_GeomFromText('POINT Z(1 1 1)'));
----
true

-- HasZ for a 3DM geometry
SELECT ST_HasZ(ST_GeomFromText('POINT M(1 1 1)'));
----
false

-- HasZ for a 4D geometry
SELECT ST_HasZ(ST_GeomFromText('POINT ZM(1 1 1 1)'));
----
true

ST_Hilbert

Signatures

UINTEGER ST_Hilbert (col0 DOUBLE, col1 DOUBLE, col2 BOX_2D)
UINTEGER ST_Hilbert (col0 GEOMETRY, col1 BOX_2D)
UINTEGER ST_Hilbert (col0 BOX_2D, col1 BOX_2D)
UINTEGER ST_Hilbert (col0 BOX_2DF, col1 BOX_2DF)
UINTEGER ST_Hilbert (col0 GEOMETRY)

Description

Encodes the X and Y values as the hilbert curve index for a curve covering the given bounding box. If a geometry is provided, the center of the approximate bounding box is used as the point to encode. If no bounding box is provided, the hilbert curve index is mapped to the full range of a single-presicion float. For the BOX_2D and BOX_2DF variants, the center of the box is used as the point to encode.

ST_Intersection

Signature

GEOMETRY ST_Intersection (geom1 GEOMETRY, geom2 GEOMETRY)

Description

Returns the "intersection" of geom1 and geom2

ST_Intersects

Signatures

BOOLEAN ST_Intersects (col0 BOX_2D, col1 BOX_2D)
BOOLEAN ST_Intersects (col0 GEOMETRY, col1 GEOMETRY)

Description

Returns true if two geometries intersects

ST_Intersects_Extent

Signature

BOOLEAN ST_Intersects_Extent (col0 GEOMETRY, col1 GEOMETRY)

Description

Returns true if the extent of two geometries intersects

ST_IsClosed

Signature

BOOLEAN ST_IsClosed (col0 GEOMETRY)

Description

Returns true if a geometry is "closed"

ST_IsEmpty

Signatures

BOOLEAN ST_IsEmpty (col0 LINESTRING_2D)
BOOLEAN ST_IsEmpty (col0 POLYGON_2D)
BOOLEAN ST_IsEmpty (col0 GEOMETRY)

Description

Returns true if the geometry is "empty"

ST_IsRing

Signature

BOOLEAN ST_IsRing (col0 GEOMETRY)

Description

Returns true if the input line geometry is a ring (both ST_IsClosed and ST_IsSimple).

ST_IsSimple

Signature

BOOLEAN ST_IsSimple (col0 GEOMETRY)

Description

Returns true if the input geometry is "simple"

ST_IsValid

Signature

BOOLEAN ST_IsValid (col0 GEOMETRY)

Description

Returns true if the geometry is topologically "valid"

ST_Length

Signatures

DOUBLE ST_Length (col0 LINESTRING_2D)
DOUBLE ST_Length (col0 GEOMETRY)

Description

Returns the length of the input line geometry

ST_Length_Spheroid

Signatures

DOUBLE ST_Length_Spheroid (col0 LINESTRING_2D)
DOUBLE ST_Length_Spheroid (col0 GEOMETRY)

Description

Returns the length of the input geometry in meters, using a ellipsoidal model of the earth

The input geometry is assumed to be in the EPSG:4326 coordinate system (WGS84), with [latitude, longitude] axis order and the length is returned in square meters. This function uses the GeographicLib library, calculating the length using an ellipsoidal model of the earth. This is a highly accurate method for calculating the length of a line geometry taking the curvature of the earth into account, but is also the slowest.

Returns 0.0 for any geometry that is not a LINESTRING, MULTILINESTRING or GEOMETRYCOLLECTION containing line geometries.

ST_LineMerge

Signatures

GEOMETRY ST_LineMerge (col0 GEOMETRY)
GEOMETRY ST_LineMerge (col0 GEOMETRY, col1 BOOLEAN)

Description

"Merges" the input line geometry, optionally taking direction into account.

ST_M

Signature

DOUBLE ST_M (col0 GEOMETRY)

Description

Returns the M value of a point geometry, or NULL if not a point or empty

ST_MMax

Signature

DOUBLE ST_MMax (col0 GEOMETRY)

Description

Returns the maximum M value of a geometry

ST_MMin

Signature

DOUBLE ST_MMin (col0 GEOMETRY)

Description

Returns the minimum M value of a geometry

ST_MakeEnvelope

Signature

GEOMETRY ST_MakeEnvelope (min_x DOUBLE, min_y DOUBLE, max_x DOUBLE, max_y DOUBLE)

Description

Returns a minimal bounding box polygon enclosing the input geometry

ST_MakeLine

Signatures

GEOMETRY ST_MakeLine (col0 GEOMETRY[])
GEOMETRY ST_MakeLine (col0 GEOMETRY, col1 GEOMETRY)

Description

Creates a LINESTRING geometry from a pair or list of input points

ST_MakePolygon

Signatures

GEOMETRY ST_MakePolygon (col0 GEOMETRY, col1 GEOMETRY[])
GEOMETRY ST_MakePolygon (col0 GEOMETRY)

Description

Creates a polygon from a shell geometry and an optional set of holes

ST_MakeValid

Signature

GEOMETRY ST_MakeValid (col0 GEOMETRY)

Description

Attempts to make an invalid geometry valid without removing any vertices

ST_Multi

Signature

GEOMETRY ST_Multi (col0 GEOMETRY)

Description

Turns a single geometry into a multi geometry.

If the geometry is already a multi geometry, it is returned as is.

Example

SELECT ST_Multi(ST_GeomFromText('POINT(1 2)'));
-- MULTIPOINT (1 2)

SELECT ST_Multi(ST_GeomFromText('LINESTRING(1 1, 2 2)'));
-- MULTILINESTRING ((1 1, 2 2))

SELECT ST_Multi(ST_GeomFromText('POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))'));
-- MULTIPOLYGON (((0 0, 0 1, 1 1, 1 0, 0 0)))

ST_NGeometries

Signature

INTEGER ST_NGeometries (col0 GEOMETRY)

Description

Returns the number of component geometries in a collection geometry. If the input geometry is not a collection, this function returns 0 or 1 depending on if the geometry is empty or not.

ST_NInteriorRings

Signatures

INTEGER ST_NInteriorRings (col0 POLYGON_2D)
INTEGER ST_NInteriorRings (col0 GEOMETRY)

Description

Returns the number if interior rings of a polygon

ST_NPoints

Signatures

UBIGINT ST_NPoints (col0 POINT_2D)
UBIGINT ST_NPoints (col0 LINESTRING_2D)
UBIGINT ST_NPoints (col0 POLYGON_2D)
UBIGINT ST_NPoints (col0 BOX_2D)
UINTEGER ST_NPoints (col0 GEOMETRY)

Description

Returns the number of vertices within a geometry

ST_Normalize

Signature

GEOMETRY ST_Normalize (col0 GEOMETRY)

Description

Returns a "normalized" version of the input geometry.

ST_NumGeometries

Signature

INTEGER ST_NumGeometries (col0 GEOMETRY)

Description

Returns the number of component geometries in a collection geometry. If the input geometry is not a collection, this function returns 0 or 1 depending on if the geometry is empty or not.

ST_NumInteriorRings

Signatures

INTEGER ST_NumInteriorRings (col0 POLYGON_2D)
INTEGER ST_NumInteriorRings (col0 GEOMETRY)

Description

Returns the number if interior rings of a polygon

ST_NumPoints

Signatures

UBIGINT ST_NumPoints (col0 POINT_2D)
UBIGINT ST_NumPoints (col0 LINESTRING_2D)
UBIGINT ST_NumPoints (col0 POLYGON_2D)
UBIGINT ST_NumPoints (col0 BOX_2D)
UINTEGER ST_NumPoints (col0 GEOMETRY)

Description

Returns the number of vertices within a geometry

ST_Overlaps

Signature

BOOLEAN ST_Overlaps (geom1 GEOMETRY, geom2 GEOMETRY)

Description

Returns true if geom1 "overlaps" geom2

ST_Perimeter

Signatures

DOUBLE ST_Perimeter (col0 BOX_2D)
DOUBLE ST_Perimeter (col0 POLYGON_2D)
DOUBLE ST_Perimeter (col0 GEOMETRY)

Description

Returns the length of the perimeter of the geometry

ST_Perimeter_Spheroid

Signatures

DOUBLE ST_Perimeter_Spheroid (col0 POLYGON_2D)
DOUBLE ST_Perimeter_Spheroid (col0 GEOMETRY)

Description

Returns the length of the perimeter in meters using an ellipsoidal model of the earths surface

The input geometry is assumed to be in the EPSG:4326 coordinate system (WGS84), with [latitude, longitude] axis order and the length is returned in meters. This function uses the GeographicLib library, calculating the perimeter using an ellipsoidal model of the earth. This is a highly accurate method for calculating the perimeter of a polygon taking the curvature of the earth into account, but is also the slowest.

Returns 0.0 for any geometry that is not a POLYGON, MULTIPOLYGON or GEOMETRYCOLLECTION containing polygon geometries.

ST_Point

Signature

GEOMETRY ST_Point (x DOUBLE, y DOUBLE)

Description

Creates a GEOMETRY point

ST_Point2D

Signature

POINT_2D ST_Point2D (x DOUBLE, y DOUBLE)

Description

Creates a POINT_2D

ST_Point3D

Signature

POINT_3D ST_Point3D (x DOUBLE, y DOUBLE, z DOUBLE)

Description

Creates a POINT_3D

ST_Point4D

Signature

POINT_4D ST_Point4D (x DOUBLE, y DOUBLE, z DOUBLE, m DOUBLE)

Description

Creates a POINT_4D

ST_PointN

Signatures

GEOMETRY ST_PointN (col0 GEOMETRY, col1 INTEGER)
POINT_2D ST_PointN (col0 LINESTRING_2D, col1 INTEGER)

Description

Returns the n'th vertex from the input geometry as a point geometry

ST_PointOnSurface

Signature

GEOMETRY ST_PointOnSurface (col0 GEOMETRY)

Description

Returns a point that is guaranteed to be on the surface of the input geometry. Sometimes a useful alternative to ST_Centroid.

ST_Points

Signature

GEOMETRY ST_Points (col0 GEOMETRY)

Description

Collects all the vertices in the geometry into a multipoint

Example

select st_points('LINESTRING(1 1, 2 2)'::geometry);
----
MULTIPOINT (1 1, 2 2)

select st_points('MULTIPOLYGON Z EMPTY'::geometry);
----
MULTIPOINT Z EMPTY

ST_QuadKey

Signatures

VARCHAR ST_QuadKey (lon DOUBLE, lat DOUBLE, level INTEGER)
VARCHAR ST_QuadKey (point GEOMETRY, level INTEGER)

Description

Compute the quadkey for a given lon/lat point at a given level. Note that the parameter order is longitude, latitude.

level has to be between 1 and 23, inclusive.

The input coordinates will be clamped to the lon/lat bounds of the earth (longitude between -180 and 180, latitude between -85.05112878 and 85.05112878).

The geometry overload throws an error if the input geometry is not a POINT

Example

SELECT ST_QuadKey(st_point(11.08, 49.45), 10);
----
1333203202

ST_ReducePrecision

Signature

GEOMETRY ST_ReducePrecision (col0 GEOMETRY, col1 DOUBLE)

Description

Returns the geometry with all vertices reduced to the target precision

ST_RemoveRepeatedPoints

Signatures

LINESTRING_2D ST_RemoveRepeatedPoints (col0 LINESTRING_2D)
LINESTRING_2D ST_RemoveRepeatedPoints (col0 LINESTRING_2D, col1 DOUBLE)
GEOMETRY ST_RemoveRepeatedPoints (col0 GEOMETRY)
GEOMETRY ST_RemoveRepeatedPoints (col0 GEOMETRY, col1 DOUBLE)

Description

Returns a new geometry with repeated points removed, optionally within a target distance of eachother.

ST_Reverse

Signature

GEOMETRY ST_Reverse (col0 GEOMETRY)

Description

Returns a new version of the input geometry with the order of its vertices reversed

ST_ShortestLine

Signature

GEOMETRY ST_ShortestLine (geom1 GEOMETRY, geom2 GEOMETRY)

Description

Returns the line between the two closest points between geom1 and geom2

ST_Simplify

Signature

GEOMETRY ST_Simplify (col0 GEOMETRY, col1 DOUBLE)

Description

Simplifies the input geometry by collapsing edges smaller than 'distance'

ST_SimplifyPreserveTopology

Signature

GEOMETRY ST_SimplifyPreserveTopology (col0 GEOMETRY, col1 DOUBLE)

Description

Returns a simplified geometry but avoids creating invalid topologies

ST_StartPoint

Signatures

GEOMETRY ST_StartPoint (col0 GEOMETRY)
POINT_2D ST_StartPoint (col0 LINESTRING_2D)

Description

Returns the first point of a line geometry

Example

select ST_StartPoint('LINESTRING(0 0, 1 1)'::geometry);
-- POINT(0 0)

ST_Touches

Signature

BOOLEAN ST_Touches (geom1 GEOMETRY, geom2 GEOMETRY)

Description

Returns true if geom1 "touches" geom2

ST_Transform

Signatures

BOX_2D ST_Transform (geom BOX_2D, source_crs VARCHAR, target_crs VARCHAR)
BOX_2D ST_Transform (geom BOX_2D, source_crs VARCHAR, target_crs VARCHAR, always_xy BOOLEAN)
POINT_2D ST_Transform (geom POINT_2D, source_crs VARCHAR, target_crs VARCHAR)
POINT_2D ST_Transform (geom POINT_2D, source_crs VARCHAR, target_crs VARCHAR, always_xy BOOLEAN)
GEOMETRY ST_Transform (geom GEOMETRY, source_crs VARCHAR, target_crs VARCHAR)
GEOMETRY ST_Transform (geom GEOMETRY, source_crs VARCHAR, target_crs VARCHAR, always_xy BOOLEAN)

Description

Transforms a geometry between two coordinate systems

The source and target coordinate systems can be specified using any format that the PROJ library supports.

The third optional always_xy parameter can be used to force the input and output geometries to be interpreted as having a [easting, northing] coordinate axis order regardless of what the source and target coordinate system definition says. This is particularly useful when transforming to/from the WGS84/EPSG:4326 coordinate system (what most people think of when they hear "longitude"/"latitude" or "GPS coordinates"), which is defined as having a [latitude, longitude] axis order even though [longitude, latitude] is commonly used in practice (e.g. in GeoJSON). More details available in the PROJ documentation.

DuckDB spatial vendors its own static copy of the PROJ database of coordinate systems, so if you have your own installation of PROJ on your system the available coordinate systems may differ to what's available in other GIS software.

Example

-- Transform a geometry from EPSG:4326 to EPSG:3857 (WGS84 to WebMercator)
-- Note that since WGS84 is defined as having a [latitude, longitude] axis order
-- we follow the standard and provide the input geometry using that axis order,
-- but the output will be [easting, northing] because that is what's defined by
-- WebMercator.

SELECT ST_AsText(
    ST_Transform(
        st_point(52.373123, 4.892360),
        'EPSG:4326',
        'EPSG:3857'
    )
);
----
POINT (544615.0239773799 6867874.103539125)

-- Alternatively, let's say we got our input point from e.g. a GeoJSON file,
-- which uses WGS84 but with [longitude, latitude] axis order. We can use the
-- `always_xy` parameter to force the input geometry to be interpreted as having
-- a [northing, easting] axis order instead, even though the source coordinate
-- reference system definition (WGS84) says otherwise.

SELECT ST_AsText(
    ST_Transform(
        -- note the axis order is reversed here
        st_point(4.892360, 52.373123),
        'EPSG:4326',
        'EPSG:3857',
        always_xy := true
    )
);
----
POINT (544615.0239773799 6867874.103539125)

ST_Union

Signature

GEOMETRY ST_Union (col0 GEOMETRY, col1 GEOMETRY)

Description

Returns the union of two geometries.

Example

SELECT ST_AsText(
    ST_Union(
        ST_GeomFromText('POINT(1 2)'),
        ST_GeomFromText('POINT(3 4)')
    )
);
----
MULTIPOINT (1 2, 3 4)

ST_Within

Signatures

BOOLEAN ST_Within (geom1 POINT_2D, geom2 POLYGON_2D)
BOOLEAN ST_Within (geom1 GEOMETRY, geom2 GEOMETRY)

Description

Returns true if geom1 is "within" geom2

ST_X

Signatures

DOUBLE ST_X (col0 POINT_2D)
DOUBLE ST_X (col0 GEOMETRY)

Description

Returns the X value of a point geometry, or NULL if not a point or empty

ST_XMax

Signatures

DOUBLE ST_XMax (col0 BOX_2D)
FLOAT ST_XMax (col0 BOX_2DF)
DOUBLE ST_XMax (col0 POINT_2D)
DOUBLE ST_XMax (col0 LINESTRING_2D)
DOUBLE ST_XMax (col0 POLYGON_2D)
DOUBLE ST_XMax (col0 GEOMETRY)

Description

Returns the maximum X value of a geometry

ST_XMin

Signatures

DOUBLE ST_XMin (col0 BOX_2D)
FLOAT ST_XMin (col0 BOX_2DF)
DOUBLE ST_XMin (col0 POINT_2D)
DOUBLE ST_XMin (col0 LINESTRING_2D)
DOUBLE ST_XMin (col0 POLYGON_2D)
DOUBLE ST_XMin (col0 GEOMETRY)

Description

Returns the minimum X value of a geometry

ST_Y

Signatures

DOUBLE ST_Y (col0 POINT_2D)
DOUBLE ST_Y (col0 GEOMETRY)

Description

Returns the Y value of a point geometry, or NULL if not a point or empty

ST_YMax

Signatures

DOUBLE ST_YMax (col0 BOX_2D)
FLOAT ST_YMax (col0 BOX_2DF)
DOUBLE ST_YMax (col0 POINT_2D)
DOUBLE ST_YMax (col0 LINESTRING_2D)
DOUBLE ST_YMax (col0 POLYGON_2D)
DOUBLE ST_YMax (col0 GEOMETRY)

Description

Returns the maximum Y value of a geometry

ST_YMin

Signatures

DOUBLE ST_YMin (col0 BOX_2D)
FLOAT ST_YMin (col0 BOX_2DF)
DOUBLE ST_YMin (col0 POINT_2D)
DOUBLE ST_YMin (col0 LINESTRING_2D)
DOUBLE ST_YMin (col0 POLYGON_2D)
DOUBLE ST_YMin (col0 GEOMETRY)

Description

Returns the minimum Y value of a geometry

ST_Z

Signature

DOUBLE ST_Z (col0 GEOMETRY)

Description

Returns the Z value of a point geometry, or NULL if not a point or empty

ST_ZMFlag

Signatures

UTINYINT ST_ZMFlag (col0 GEOMETRY)
UTINYINT ST_ZMFlag (col0 WKB_BLOB)

Description

Returns a flag indicating the presence of Z and M values in the input geometry. 0 = No Z or M values 1 = M values only 2 = Z values only 3 = Z and M values

Example

-- ZMFlag for a 2D geometry
SELECT ST_ZMFlag(ST_GeomFromText('POINT(1 1)'));
----
0

-- ZMFlag for a 3DZ geometry
SELECT ST_ZMFlag(ST_GeomFromText('POINT Z(1 1 1)'));
----
2

-- ZMFlag for a 3DM geometry
SELECT ST_ZMFlag(ST_GeomFromText('POINT M(1 1 1)'));
----
1

-- ZMFlag for a 4D geometry
SELECT ST_ZMFlag(ST_GeomFromText('POINT ZM(1 1 1 1)'));
----
3

ST_ZMax

Signature

DOUBLE ST_ZMax (col0 GEOMETRY)

Description

Returns the maximum Z value of a geometry

ST_ZMin

Signature

DOUBLE ST_ZMin (col0 GEOMETRY)

Description

Returns the minimum Z value of a geometry

Aggregate Functions

ST_Envelope_Agg

Signature

GEOMETRY ST_Envelope_Agg (col0 GEOMETRY)

Description

Alias for ST_Extent_Agg.

Computes the minimal-bounding-box polygon containing the set of input geometries.

Example

SELECT ST_Extent_Agg(geom) FROM UNNEST([ST_Point(1,1), ST_Point(5,5)]) AS _(geom);
-- POLYGON ((1 1, 1 5, 5 5, 5 1, 1 1))

ST_Extent_Agg

Signature

GEOMETRY ST_Extent_Agg (col0 GEOMETRY)

Description

Computes the minimal-bounding-box polygon containing the set of input geometries

Example

SELECT ST_Extent_Agg(geom) FROM UNNEST([ST_Point(1,1), ST_Point(5,5)]) AS _(geom);
-- POLYGON ((1 1, 1 5, 5 5, 5 1, 1 1))

ST_Intersection_Agg

Signature

GEOMETRY ST_Intersection_Agg (col0 GEOMETRY)

Description

Computes the intersection of a set of geometries

ST_Union_Agg

Signature

GEOMETRY ST_Union_Agg (col0 GEOMETRY)

Description

Computes the union of a set of input geometries

Table Functions

ST_Drivers

Signature

ST_Drivers ()

Description

Returns the list of supported GDAL drivers and file formats

Note that far from all of these drivers have been tested properly, and some may require additional options to be passed to work as expected. If you run into any issues please first consult the consult the GDAL docs.

Example

SELECT * FROM ST_Drivers();

ST_Read

Signature

ST_Read (col0 VARCHAR, keep_wkb BOOLEAN, max_batch_size INTEGER, sequential_layer_scan BOOLEAN, layer VARCHAR, sibling_files VARCHAR[], spatial_filter WKB_BLOB, spatial_filter_box BOX_2D, allowed_drivers VARCHAR[], open_options VARCHAR[])

Description

Read and import a variety of geospatial file formats using the GDAL library.

The ST_Read table function is based on the GDAL translator library and enables reading spatial data from a variety of geospatial vector file formats as if they were DuckDB tables.

See ST_Drivers for a list of supported file formats and drivers.

Except for the path parameter, all parameters are optional.

Parameter Type Description
path VARCHAR The path to the file to read. Mandatory
sequential_layer_scan BOOLEAN If set to true, the table function will scan through all layers sequentially and return the first layer that matches the given layer name. This is required for some drivers to work properly, e.g., the OSM driver.
spatial_filter WKB_BLOB If set to a WKB blob, the table function will only return rows that intersect with the given WKB geometry. Some drivers may support efficient spatial filtering natively, in which case it will be pushed down. Otherwise the filtering is done by GDAL which may be much slower.
open_options VARCHAR[] A list of key-value pairs that are passed to the GDAL driver to control the opening of the file. E.g., the GeoJSON driver supports a FLATTEN_NESTED_ATTRIBUTES=YES option to flatten nested attributes.
layer VARCHAR The name of the layer to read from the file. If NULL, the first layer is returned. Can also be a layer index (starting at 0).
allowed_drivers VARCHAR[] A list of GDAL driver names that are allowed to be used to open the file. If empty, all drivers are allowed.
sibling_files VARCHAR[] A list of sibling files that are required to open the file. E.g., the ESRI Shapefile driver requires a .shx file to be present. Although most of the time these can be discovered automatically.
spatial_filter_box BOX_2D If set to a BOX_2D, the table function will only return rows that intersect with the given bounding box. Similar to spatial_filter.
keep_wkb BOOLEAN If set, the table function will return geometries in a wkb_geometry column with the type WKB_BLOB (which can be cast to BLOB) instead of GEOMETRY. This is useful if you want to use DuckDB with more exotic geometry subtypes that DuckDB spatial doesnt support representing in the GEOMETRY type yet.

Note that GDAL is single-threaded, so this table function will not be able to make full use of parallelism.

By using ST_Read, the spatial extension also provides “replacement scans” for common geospatial file formats, allowing you to query files of these formats as if they were tables directly.

SELECT * FROM './path/to/some/shapefile/dataset.shp';

In practice this is just syntax-sugar for calling ST_Read, so there is no difference in performance. If you want to pass additional options, you should use the ST_Read table function directly.

The following formats are currently recognized by their file extension:

Format Extension
ESRI ShapeFile .shp
GeoPackage .gpkg
FlatGeoBuf .fgb

Example

-- Read a Shapefile
SELECT * FROM ST_Read('some/file/path/filename.shp');

-- Read a GeoJSON file
CREATE TABLE my_geojson_table AS SELECT * FROM ST_Read('some/file/path/filename.json');

ST_ReadOSM

Signature

ST_ReadOSM (col0 VARCHAR)

Description

The ST_ReadOsm() table function enables reading compressed OpenStreetMap data directly from a .osm.pbf file.

This function uses multithreading and zero-copy protobuf parsing which makes it a lot faster than using the ST_Read() OSM driver, however it only outputs the raw OSM data (Nodes, Ways, Relations), without constructing any geometries. For simple node entities (like PoI's) you can trivially construct POINT geometries, but it is also possible to construct LINESTRING and POLYGON geometries by manually joining refs and nodes together in SQL, although with available memory usually being a limiting factor. The ST_ReadOSM() function also provides a "replacement scan" to enable reading from a file directly as if it were a table. This is just syntax sugar for calling ST_ReadOSM() though. Example:

SELECT * FROM 'tmp/data/germany.osm.pbf' LIMIT 5;

Example

SELECT *
FROM ST_ReadOSM('tmp/data/germany.osm.pbf')
WHERE tags['highway'] != []
LIMIT 5;
----
┌──────────────────────┬────────┬──────────────────────┬─────────┬────────────────────┬────────────┬───────────┬────────────────────────┐
│         kind         │   id   │         tags         │  refs   │        lat         │    lon     │ ref_roles │       ref_types        │
│ enum('node', 'way'…  │ int64  │ map(varchar, varch…  │ int64[] │       double       │   double   │ varchar[] │ enum('node', 'way', …  │
├──────────────────────┼────────┼──────────────────────┼─────────┼────────────────────┼────────────┼───────────┼────────────────────────┤
│ node                 │ 122351 │ {bicycle=yes, butt…  │         │         53.5492951 │   9.977553 │           │                        │
│ node                 │ 122397 │ {crossing=no, high…  │         │ 53.520990100000006 │ 10.0156924 │           │                        │
│ node                 │ 122493 │ {TMC:cid_58:tabcd_…  │         │ 53.129614600000004 │  8.1970173 │           │                        │
│ node                 │ 123566 │ {highway=traffic_s…  │         │ 54.617268200000005 │  8.9718171 │           │                        │
│ node                 │ 125801 │ {TMC:cid_58:tabcd_…  │         │ 53.070685000000005 │  8.7819939 │           │                        │
└──────────────────────┴────────┴──────────────────────┴─────────┴────────────────────┴────────────┴───────────┴────────────────────────┘

ST_Read_Meta

Signature

ST_Read_Meta (col0 VARCHAR)
ST_Read_Meta (col0 VARCHAR[])

Description

Read the metadata from a variety of geospatial file formats using the GDAL library.

The ST_Read_Meta table function accompanies the ST_Read table function, but instead of reading the contents of a file, this function scans the metadata instead. Since the data model of the underlying GDAL library is quite flexible, most of the interesting metadata is within the returned layers column, which is a somewhat complex nested structure of DuckDB STRUCT and LIST types.

Example

-- Find the coordinate reference system authority name and code for the first layers first geometry column in the file
SELECT
    layers[1].geometry_fields[1].crs.auth_name as name,
    layers[1].geometry_fields[1].crs.auth_code as code
FROM st_read_meta('../../tmp/data/amsterdam_roads.fgb');