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Geo Polygon functions

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Autogenerated from ClickHouse system tables

MVTEncodeGeom

Introduced in: v26.7.0

Projects a geometry given in geographic coordinates (longitude/latitude) into the tile-local pixel space of the slippy-map tile identified by zoom, tile_x and tile_y, snaps it to the integer pixel grid, optionally clips it to the tile, and returns the tile-space geometry as a Geometry.

The projection is Web Mercator over the full UInt32 coordinate range; the origin is the tile’s top-left corner with the y axis pointing downwards (the Mapbox Vector Tile convention). When clip is enabled (the default) the geometry is clipped to the tile expanded by buffer pixels, and geometries that fall entirely outside become NULL. The result is intended to be passed to the aggregate function MVTEncode. This function is the analogue of PostGIS ST_AsMVTGeom.

Supported input geometry types are Point, MultiPoint, LineString, MultiLineString, Ring, Polygon, MultiPolygon and the Geometry variant.

Syntax

MVTEncodeGeom(geometry, zoom, tile_x, tile_y[, extent[, buffer[, clip]]])

Arguments

  • geometry — Geometry in longitude/latitude degrees. Point or MultiPoint or LineString or MultiLineString or Ring or Polygon or MultiPolygon or Geometry
  • zoom — Slippy-map zoom level, in the range [0, 32]. UInt8
  • tile_x — Tile column index, in the range [0, 2^zoom - 1]. UInt32
  • tile_y — Tile row index, in the range [0, 2^zoom - 1]. UInt32
  • extent — Optional tile extent in pixels per side. Defaults to 4096. UInt32
  • buffer — Optional clip buffer in pixels. Defaults to 1. UInt32
  • clip — Optional flag; when nonzero (default) the geometry is clipped to the tile plus buffer. UInt8

Returned value

Returns the tile-space geometry, or NULL if it is fully clipped out. Geometry

Examples

Project a point into a tile

SELECT MVTEncodeGeom((13.37, 52.52)::Point, 10, 550, 335)
┌─MVTEncodeGeom(CAST('(13.37, 52.52)', 'Point'), 10, 550, 335)─┐
│ (124,3384)                                                   │
└──────────────────────────────────────────────────────────────┘

polygonAreaCartesian

Introduced in: v21.4.0

Calculates the area of a polygon.

Syntax

polygonAreaCartesian(polygon)

Arguments

  • polygon — A polygon value Polygon

Returned value

Returns the area of the polygon Float64

Examples

Usage example

SELECT polygonAreaCartesian([[[(0., 0.), (0., 5.), (5., 5.), (5., 0.)]]])
25

polygonAreaSpherical

Introduced in: v21.4.0

Calculates the surface area of a polygon.

Syntax

polygonAreaSpherical(polygon)

Arguments

  • polygon — A polygon value. Polygon

Returned value

Returns the surface area of the polygon Float64

Examples

Spherical example

SELECT round(polygonAreaSpherical([[[(4.346693, 50.858306), (4.367945, 50.852455), (4.366227, 50.840809), (4.344961, 50.833264), (4.338074, 50.848677), (4.346693, 50.858306)]]]), 14)
9.387704e-8

polygonConvexHullCartesian

Introduced in: v21.4.0

Calculates a convex hull. Reference

Coordinates are in Cartesian coordinate system.

Syntax

polygonConvexHullCartesian(multipolygon)

Arguments

Returned value

Returns the convex hull as a Polygon. Polygon

Examples

Conve hull example

SELECT wkt(polygonConvexHullCartesian([[[(0., 0.), (0., 5.), (5., 5.), (5., 0.), (2., 3.)]]]))
POLYGON((0 0,0 5,5 5,5 0,0 0))

polygonPerimeterCartesian

Introduced in: v21.4.0

Calculates the perimeter of a polygon.

Syntax

polygonPerimeterCartesian(polygon)

Arguments

  • polygon — A Polygon value. Polygon

Returned value

Returns the perimeter of the polygon. Float64

Examples

Usage example

SELECT polygonPerimeterCartesian([[[(0., 0.), (0., 5.), (5., 5.), (5., 0.)]]])
15

polygonPerimeterSpherical

Introduced in: v21.4.0

Calculates the perimeter of the polygon.

Syntax

polygonPerimeterSpherical(polygon)

Arguments

  • polygon — A value of type Polygon

Returned value

The perimeter of the polygon on a sphere Float64

Examples

spherical_example

SELECT round(polygonPerimeterSpherical([[[(4.346693, 50.858306), (4.367945, 50.852455), (4.366227, 50.840809), (4.344961, 50.833264), (4.338074, 50.848677), (4.346693, 50.858306)]]]), 6)
0.001201

polygonsDistanceCartesian

Introduced in: v21.4.0

Calculates distance between two polygons.

Syntax

polygonsDistanceCartesian(polygon1, polygon2)

Arguments

  • polygon1 — A Polygon value Polygon
  • polygon2 — A Polygon value Polygon

Returned value

Returns the minimal distance between the two polygons Float64

Examples

Distance example

SELECT polygonsDistanceCartesian([[[(0, 0), (0, 0.1), (0.1, 0.1), (0.1, 0)]]], [[[(10., 10.), (10., 40.), (40., 40.), (40., 10.), (10., 10.)]]])
14.000714267493642

polygonsDistanceSpherical

Introduced in: v21.4.0

Calculates the minimal distance between two points where one point belongs to the first polygon and the second to another polygon. Spherical means that coordinates are interpreted as coordinates on a pure and ideal sphere, which is not true for the Earth. Using this type of coordinate system speeds up execution, but of course is not precise.

Syntax

polygonsDistanceSpherical(polygon1, polygon2)

Arguments

  • polygon1 — The first Polygon value. Polygon
  • polygon2 — The second Polygon value. Polygon

Returned value

Returns the minimal distance between the two polygons on a sphere Float64

Examples

Spherical distance

SELECT polygonsDistanceSpherical([[[(0, 0), (0, 0.1), (0.1, 0.1), (0.1, 0)]]], [[[(10., 10.), (10., 40.), (40., 40.), (40., 10.), (10., 10.)]]])
0.24372872211133823

polygonsEqualsCartesian

Introduced in: v21.4.0

Returns true if two polygons are equal.

Syntax

polygonsEqualsCartesian(polygon1, polygon2)

Arguments

  • polygon1 — The first Polygon. Polygon
  • polygon2 — The second Polygon. Polygon

Returned value

Returns 1 if equal, otherwise 0. UInt8

Examples

Equality check example

SELECT polygonsEqualsCartesian([[[(1., 1.), (1., 4.), (4., 4.), (4., 1.)]]], [[[(1., 1.), (1., 4.), (4., 4.), (4., 1.), (1., 1.)]]])
1

polygonsIntersectionCartesian

Introduced in: v21.4.0

Calculates the intersection of polygons.

Syntax

polygonsIntersectionCartesian(polygon1, polygon2)

Arguments

  • polygon1 — The first Polygon. Polygon
  • polygon2 — The second Polygon. Polygon

Returned value

Returns the intersection of the polygons as a MultiPolygon. MultiPolygon

Examples

Intersection example

SELECT wkt(polygonsIntersectionCartesian([[[(0., 0.), (0., 3.), (1., 2.9), (2., 2.6), (2.6, 2.), (2.9, 1.), (3., 0.), (0., 0.)]]], [[[(1., 1.), (1., 4.), (4., 4.), (4., 1.), (1., 1.)]]]))
MULTIPOLYGON(((1 2.9,2 2.6,2.6 2,2.9 1,1 1,1 2.9)))

polygonsIntersectionSpherical

Introduced in: v21.4.0

Calculates the intersection (AND) between polygons, coordinates are spherical.

Syntax

polygonsIntersectionSpherical(polygon1, polygon2)

Arguments

  • polygon1 — First Polygon with spherical coordinates. Polygon
  • polygon2 — Second Polygon with spherical coordinates. Polygon

Returned value

Returns the intersection of the polygons as a MultiPolygon. MultiPolygon

Examples

Spherical intersection example

SELECT wkt(arrayMap(a -> arrayMap(b -> arrayMap(c -> (round(c.1, 6), round(c.2, 6)), b), a), polygonsIntersectionSpherical([[[(4.3613577, 50.8651821), (4.349556, 50.8535879), (4.3602419, 50.8435626), (4.3830299, 50.8428851), (4.3904543, 50.8564867), (4.3613148, 50.8651279)]]], [[[(4.346693, 50.858306), (4.367945, 50.852455), (4.366227, 50.840809), (4.344961, 50.833264), (4.338074, 50.848677), (4.346693, 50.858306)]]])))
MULTIPOLYGON(((4.3666 50.8434,4.36024 50.8436,4.34956 50.8536,4.35268 50.8567,4.36794 50.8525,4.3666 50.8434)))

polygonsSymDifferenceCartesian

Introduced in: v21.4.0

The same as polygonsSymDifferenceSpherical, but the coordinates are in the Cartesian coordinate system; which is more close to the model of the real Earth.

Syntax

polygonsSymDifferenceCartesian(polygon1, polygon2)

Arguments

  • polygon1 — The first Polygon. Polygon
  • polygon2 — The second Polygon Polygon

Returned value

Returns the symmetric difference of the polygons as a MultiPolygon. MultiPolygon

Examples

Usage example

SELECT wkt(polygonsSymDifferenceCartesian([[[(0, 0), (0, 3), (1, 2.9), (2, 2.6), (2.6, 2), (2.9, 1), (3, 0), (0, 0)]]], [[[(1., 1.), (1., 4.), (4., 4.), (4., 1.), (1., 1.)]]]))
MULTIPOLYGON(((1 2.9,1 1,2.9 1,3 0,0 0,0 3,1 2.9)),((1 2.9,1 4,4 4,4 1,2.9 1,2.6 2,2 2.6,1 2.9)))

polygonsSymDifferenceSpherical

Introduced in: v21.4.0

Calculates the spatial set theoretic symmetric difference (XOR) between two polygons

Syntax

polygonsSymDifferenceSpherical(polygon1, polygon2)

Arguments

  • polygon1 — The first Polygon. Polygon
  • polygon2 — The second Polygon Polygon

Returned value

Returns the symmetric difference of the polygons as a MultiPolygon. MultiPolygon

Examples

Usage example

SELECT wkt(arraySort(polygonsSymDifferenceSpherical([[(50., 50.), (50., -50.), (-50., -50.), (-50., 50.), (50., 50.)], [(10., 10.), (10., 40.), (40., 40.), (40., 10.), (10., 10.)], [(-10., -10.), (-10., -40.), (-40., -40.), (-40., -10.), (-10., -10.)]], [[(-20., -20.), (-20., 20.), (20., 20.), (20., -20.), (-20., -20.)]])));
MULTIPOLYGON(((-20 -10.3067,-10 -10,-10 -20.8791,-20 -20,-20 -10.3067)),((10 20.8791,20 20,20 10.3067,10 10,10 20.8791)),((50 50,50 -50,-50 -50,-50 50,50 50),(10 20.8791,-20 20,-20 -10.3067,-40 -10,-40 -40,-10 -40,-10 -20.8791,20 -20,20 10.3067,40 10,40 40,10 40,10 20.8791)))

polygonsUnionCartesian

Introduced in: v21.4.0

Calculates the union of polygons.

Syntax

polygonsUnionCartesian(polygon1, polygon2)

Arguments

  • polygon1 — The first Polygon. Polygon
  • polygon2 — The second Polygon. Polygon

Returned value

Returns the union of the polygons as a MultiPolygon. MultiPolygon

Examples

Usage example

SELECT wkt(polygonsUnionCartesian([[[(0., 0.), (0., 3.), (1., 2.9), (2., 2.6), (2.6, 2.), (2.9, 1), (3., 0.), (0., 0.)]]], [[[(1., 1.), (1., 4.), (4., 4.), (4., 1.), (1., 1.)]]]))
MULTIPOLYGON(((1 2.9,1 4,4 4,4 1,2.9 1,3 0,0 0,0 3,1 2.9)))

polygonsUnionSpherical

Introduced in: v21.4.0

Calculates a union (OR) of polygons.

Syntax

polygonsUnionSpherical(polygon1, polygon2)

Arguments

  • polygon1 — The first Polygon. Polygon
  • polygon2 — The second Polygon. Polygon

Returned value

Returns the union of the polygons as a MultiPolygon. MultiPolygon

Examples

Usage example

SELECT wkt(polygonsUnionSpherical([[[(4.3613577, 50.8651821), (4.349556, 50.8535879), (4.3602419, 50.8435626), (4.3830299, 50.8428851), (4.3904543, 50.8564867), (4.3613148, 50.8651279)]]], [[[(4.346693, 50.858306), (4.367945, 50.852455), (4.366227, 50.840809), (4.344961, 50.833264), (4.338074, 50.848677), (4.346693, 50.858306)]]]))
MULTIPOLYGON(((4.36661 50.8434,4.36623 50.8408,4.34496 50.8333,4.33807 50.8487,4.34669 50.8583,4.35268 50.8567,4.36136 50.8652,4.36131 50.8651,4.39045 50.8565,4.38303 50.8429,4.36661 50.8434)))

polygonsWithinCartesian

Introduced in: v21.4.0

Checks if a polygon is within another polygon.

Syntax

polygonsWithinCartesian(polygon1, polygon2)

Arguments

  • polygon1 — The first polygon. Polygon
  • polygon2 — The second polygon. Polygon

Returned value

Returns 1 if polygon1 is contained in polygon2, otherwise 0. UInt8

Examples

Usage example

SELECT polygonsWithinCartesian([[[(2., 2.), (2., 3.), (3., 3.), (3., 2.)]]], [[[(1., 1.), (1., 4.), (4., 4.), (4., 1.), (1., 1.)]]])
1

polygonsWithinSpherical

Introduced in: v21.4.0

Returns true or false depending on whether or not one polygon lies completely inside another polygon. Reference

Syntax

polygonsWithinSpherical(polygon1, polygon2)

Arguments

  • polygon1 — The first Polygon. Polygon
  • polygon2 — The second Polygon. Polygon

Returned value

Returns 1 if polygon1 lies completely within polygon2, otherwise 0. UInt8

Examples

Usage example

SELECT polygonsWithinSpherical([[[(4.3613577, 50.8651821), (4.349556, 50.8535879), (4.3602419, 50.8435626), (4.3830299, 50.8428851), (4.3904543, 50.8564867), (4.3613148, 50.8651279)]]], [[[(4.346693, 50.858306), (4.367945, 50.852455), (4.366227, 50.840809), (4.344961, 50.833264), (4.338074, 50.848677), (4.346693, 50.858306)]]]);
0

readWKBLineString

Introduced in: v25.6.0

Parses a Well-Known Binary (WKB) representation of a LineString geometry and returns it in the internal ClickHouse format.

Syntax

readWKBLineString(wkb_string)

Arguments

  • wkb_string — The input WKB string representing a LineString geometry. String

Returned value

Returns returns a ClickHouse internal representation of the linestring geometry. Geo

Examples

Usage example

SELECT readWKBLineString(unhex('010200000004000000000000000000f03f000000000000f03f0000000000000040000000000000004000000000000008400000000000000840000000000000f03f000000000000f03f'));
[(1,1),(2,2),(3,3),(1,1)]

readWKBMultiLineString

Introduced in: v25.6.0

Parses a Well-Known Binary (WKB) representation of a MultiLineString geometry and returns it in the internal ClickHouse format.

Syntax

readWKBMultiLineString(wkb_string)

Arguments

  • wkb_string — The input WKB string representing a MultiLineString geometry. String

Returned value

Returns a ClickHouse internal representation of the multilinestring geometry. Geo

Examples

Usage example

SELECT readWKBMultiLineString(unhex('010500000002000000010200000003000000000000000000f03f000000000000f03f0000000000000040000000000000004000000000000008400000000000000840010200000003000000000000000000104000000000000010400000000000001440000000000000144000000000000018400000000000001840'));
[[(1,1),(2,2),(3,3)],[(4,4),(5,5),(6,6)]]

readWKBMultiPoint

Introduced in: v26.7.0

Parses a Well-Known Binary (WKB) representation of a MultiPoint geometry and returns it in the internal ClickHouse format.

Syntax

readWKBMultiPoint(wkb_string)

Arguments

  • wkb_string — The input WKB string representing a MultiPoint geometry. String

Returned value

Returns a ClickHouse internal representation of the multipoint geometry. Geo

Examples

Usage example

SELECT readWKBMultiPoint(unhex('0104000000020000000101000000000000000000f03f000000000000f03f010100000000000000000000400000000000000040'));
[(1,1),(2,2)]

readWKBMultiPolygon

Introduced in: v25.6.0

Parses a Well-Known Binary (WKB) representation of a MultiPolygon geometry and returns it in the internal ClickHouse format.

Syntax

readWKBMultiPolygon(wkb_string)

Arguments

  • wkb_string — The input WKB string representing a MultiPolygon geometry. String

Returned value

Returns a ClickHouse internal representation of the MultiPolygon geometry. Geo

Examples

Usage example

SELECT
    toTypeName(readWKBMultiPolygon(unhex('0106000000020000000103000000020000000500000000000000000000400000000000000000000000000000244000000000000000000000000000002440000000000000244000000000000000000000000000002440000000000000004000000000000000000500000000000000000010400000000000001040000000000000144000000000000010400000000000001440000000000000144000000000000010400000000000001440000000000000104000000000000010400103000000010000000400000000000000000024c000000000000024c000000000000024c000000000000022c000000000000022c0000000000000244000000000000024c000000000000024c0'))) AS type,
    readWKBMultiPolygon(unhex('0106000000020000000103000000020000000500000000000000000000400000000000000000000000000000244000000000000000000000000000002440000000000000244000000000000000000000000000002440000000000000004000000000000000000500000000000000000010400000000000001040000000000000144000000000000010400000000000001440000000000000144000000000000010400000000000001440000000000000104000000000000010400103000000010000000400000000000000000024c000000000000024c000000000000024c000000000000022c000000000000022c0000000000000244000000000000024c000000000000024c0')) FORMAT Vertical;
Row 1:
──────
type:                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         MultiPolygon
readWKBMultiPolygon(unhex('0106000000020000000103000000020000000500000000000000000000400000000000000000000000000000244000000000000000000000000000002440000000000000244000000000000000000000000000002440000000000000004000000000000000000500000000000000000010400000000000001040000000000000144000000000000010400000000000001440000000000000144000000000000010400000000000001440000000000000104000000000000010400103000000010000000400000000000000000024c000000000000024c000000000000024c000000000000022c000000000000022c0000000000000244000000000000024c000000000000024c0')): [[[(2,0),(10,0),(10,10),(0,10),(2,0)],[(4,4),(5,4),(5,5),(4,5),(4,4)]],[[(-10,-10),(-10,-9),(-9,10),(-10,-10)]]]

readWKBPoint

Introduced in: v25.6.0

Parses a Well-Known Binary (WKB) representation of a Point geometry and returns it in the internal ClickHouse format.

Syntax

readWKBPoint(wkb_string)

Arguments

  • wkb_string — The input WKB string representing a Point geometry. String

Returned value

The function returns a ClickHouse internal representation of the point geometry. Geo

Examples

Usage example

SELECT toTypeName(readWKBPoint(unhex('0101000000333333333333f33f3333333333330b40')));
Point

readWKBPolygon

Introduced in: v25.6.0

Parses a Well-Known Binary (WKB) representation of a Polygon geometry and returns it in the internal ClickHouse format.

Syntax

readWKBPolygon(wkb_string)

Arguments

  • wkb_string — The input WKB string representing a Polygon geometry. String

Returned value

Returns a ClickHouse internal representation of the Polygon geometry. Geo

Examples

Usage example

SELECT
    toTypeName(readWKBPolygon(unhex('010300000001000000050000000000000000000040000000000000000000000000000024400000000000000000000000000000244000000000000024400000000000000000000000000000244000000000000000400000000000000000'))) AS type,
    readWKBPolygon(unhex('010300000001000000050000000000000000000040000000000000000000000000000024400000000000000000000000000000244000000000000024400000000000000000000000000000244000000000000000400000000000000000'));
Polygon	[[(2,0),(10,0),(10,10),(0,10),(2,0)]]

readWKTLineString

Introduced in: v21.4.0

Parses a Well-Known Text (WKT) representation of a LineString geometry and returns it in the internal ClickHouse format.

Syntax

readWKTLineString(wkt_string)

Arguments

  • wkt_string — The input WKT string representing a LineString geometry. String

Returned value

Returns a ClickHouse internal representation of the linestring geometry. Geo

Examples

Usage example

SELECT readWKTLineString('LINESTRING (1 1, 2 2, 3 3, 1 1)');
┌─readWKTLineString('LINESTRING (1 1, 2 2, 3 3, 1 1)')─┐
│ [(1,1),(2,2),(3,3),(1,1)]                            │
└──────────────────────────────────────────────────────┘

LineString example

SELECT toTypeName(readWKTLineString('LINESTRING (1 1, 2 2, 3 3, 1 1)'));
┌─toTypeName(readWKTLineString('LINESTRING (1 1, 2 2, 3 3, 1 1)'))─┐
│ LineString                                                       │
└──────────────────────────────────────────────────────────────────┘

readWKTMultiLineString

Introduced in: v21.4.0

Parses a Well-Known Text (WKT) representation of a MultiLineString geometry and returns it in the internal ClickHouse format.

Syntax

readWKTMultiLineString(wkt_string)

Arguments

  • wkt_string — The input WKT string representing a MultiLineString geometry. String

Returned value

Returns the function returns a ClickHouse internal representation of the multilinestring geometry. Geo

Examples

Usage example

SELECT readWKTMultiLineString('MULTILINESTRING ((1 1, 2 2, 3 3), (4 4, 5 5, 6 6))');
┌─readWKTMultiLineString('MULTILINESTRING ((1 1, 2 2, 3 3), (4 4, 5 5, 6 6))')─┐
│ [[(1,1),(2,2),(3,3)],[(4,4),(5,5),(6,6)]]                                    │
└──────────────────────────────────────────────────────────────────────────────┘

MultiLineString example

SELECT toTypeName(readWKTMultiLineString('MULTILINESTRING ((1 1, 2 2, 3 3, 1 1))'));
┌─toTypeName(readWKTMultiLineString('MULTILINESTRING ((1 1, 2 2, 3 3, 1 1))'))─┐
│ MultiLineString                                                              │
└──────────────────────────────────────────────────────────────────────────────┘

readWKTMultiPoint

Introduced in: v26.7.0

Parses a Well-Known Text (WKT) representation of a MultiPoint geometry and returns it in the internal ClickHouse format.

Syntax

readWKTMultiPoint(wkt_string)

Arguments

  • wkt_string — The input WKT string representing a MultiPoint geometry. String

Returned value

Returns a ClickHouse internal representation of the multipoint geometry. Geo

Examples

Usage example

SELECT readWKTMultiPoint('MULTIPOINT (1 1, 2 2, 3 3)');
┌─readWKTMultiPoint('MULTIPOINT (1 1, 2 2, 3 3)')─┐
│ [(1,1),(2,2),(3,3)]                             │
└─────────────────────────────────────────────────┘

MultiPoint example

SELECT toTypeName(readWKTMultiPoint('MULTIPOINT (1 1, 2 2)'));
┌─toTypeName(readWKTMultiPoint('MULTIPOINT (1 1, 2 2)'))─┐
│ MultiPoint                                             │
└────────────────────────────────────────────────────────┘

readWKTMultiPolygon

Introduced in: v21.4.0

Converts a WKT (Well Known Text) MultiPolygon into a MultiPolygon type.

Syntax

readWKTMultiPolygon(wkt_string)

Arguments

  • wkt_string — String starting with MULTIPOLYGON String

Returned value

Returns a MultiPolygon MultiPolygon

Examples

Usage example

SELECT
    toTypeName(readWKTMultiPolygon('MULTIPOLYGON(((2 0,10 0,10 10,0 10,2 0),(4 4,5 4,5 5,4 5,4 4)),((-10 -10,-10 -9,-9 10,-10 -10)))')) AS type,
    readWKTMultiPolygon('MULTIPOLYGON(((2 0,10 0,10 10,0 10,2 0),(4 4,5 4,5 5,4 5,4 4)),((-10 -10,-10 -9,-9 10,-10 -10)))') AS output
MultiPolygon	[[[(2,0),(10,0),(10,10),(0,10),(2,0)],[(4,4),(5,4),(5,5),(4,5),(4,4)]],[[(-10,-10),(-10,-9),(-9,10),(-10,-10)]]]

readWKTPoint

Introduced in: v21.4.0

The readWKTPoint function in ClickHouse parses a Well-Known Text (WKT) representation of a Point geometry and returns a point in the internal ClickHouse format.

Syntax

readWKTPoint(wkt_string)

Arguments

  • wkt_string — The input WKT string representing a Point geometry. String

Returned value

Returns a ClickHouse internal representation of the Point geometry. Geo

Examples

Usage example

SELECT readWKTPoint('POINT (1.2 3.4)');
(1.2,3.4)

readWKTPolygon

Introduced in: v21.4.0

Converts a WKT (Well Known Text) MultiPolygon into a Polygon type.

Syntax

readWKTPolygon(wkt_string)

Arguments

  • wkt_string — String starting with POLYGON String

Returned value

Returns a Polygon Polygon

Examples

Usage example

SELECT
    toTypeName(readWKTPolygon('POLYGON((2 0,10 0,10 10,0 10,2 0))')) AS type,
    readWKTPolygon('POLYGON((2 0,10 0,10 10,0 10,2 0))') AS output
Polygon	[[(2,0),(10,0),(10,10),(0,10),(2,0)]]

readWKTRing

Introduced in: v21.4.0

Parses a Well-Known Text (WKT) representation of a Polygon geometry and returns a ring (closed linestring) in the internal ClickHouse format.

Syntax

readWKTRing(wkt_string)

Arguments

  • wkt_string — The input WKT string representing a Polygon geometry. String

Returned value

Returns a ClickHouse internal representation of the ring (closed linestring) geometry. Geo

Examples

Usage example

SELECT readWKTRing('POLYGON ((1 1, 2 2, 3 3, 1 1))');
[(1,1),(2,2),(3,3),(1,1)]
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