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Functions for Working with Geometry

docs/en/sql-reference/functions/geo/geometry.md

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Geometry {#geometry}

Geometry functions allow you to calculate perimeter and area for geometric types such as POLYGON, LINESTRING, MULTIPOLYGON, MULTILINESTRING, RING, and POINT. Use geometries in Geometry type. If the input value is NULL, all functions below will return 0.

perimeterCartesian {#perimetercartesian}

Calculates the perimeter of the given Geometry object in the Cartesian (flat) coordinate system.

Syntax

sql
perimeterCartesian(geom)

Arguments

Returned values

  • Number — Perimeter of the object in the coordinate system units. Float64.

Example

sql
CREATE TABLE IF NOT EXISTS geo_dst (geom Geometry) ENGINE = Memory();
INSERT INTO geo_dst SELECT readWKT('POLYGON((0 0,1 0,1 1,0 1,0 0))');
SELECT perimeterCartesian(geom) FROM geo_dst;
response
┌─perimeterCartesian(geom)─┐
│ 4.0                      │
└──────────────────────────┘

areaCartesian {#areacartesian}

Calculates the area of the given Geometry object in the Cartesian coordinate system.

Syntax

sql
areaCartesian(geom)

Arguments

Returned values

  • Number — Area of the object in coordinate system units. Float64.

Example

sql
CREATE TABLE IF NOT EXISTS geo_dst (geom Geometry) ENGINE = Memory();
INSERT INTO geo_dst SELECT readWKT('POLYGON((0 0,1 0,1 1,0 1,0 0))');
SELECT areaCartesian(geom) FROM geo_dst;
response
┌─areaCartesian(geom)─┐
│ -1                  │
└─────────────────────┘

perimeterSpherical {#perimeterspherical}

Calculates the perimeter of a Geometry object on the surface of a sphere.

Syntax

sql
perimeterSpherical(geom)

Arguments

Returned values

Example

sql
CREATE TABLE IF NOT EXISTS geo_dst (geom Geometry) ENGINE = Memory();
INSERT INTO geo_dst SELECT readWKT('LINESTRING(0 0,1 0,1 1,0 1,0 0)');
SELECT perimeterSpherical(geom) FROM geo_dst;
response
┌─perimeterSpherical(geom)─┐
│ 0                        │
└──────────────────────────┘

areaSpherical {#areaspherical}

Calculates the area of a Geometry object on the surface of a sphere.

Syntax

sql
areaSpherical(geom)

Arguments

Returned values

Example

sql
CREATE TABLE IF NOT EXISTS geo_dst (geom Geometry) ENGINE = Memory();
INSERT INTO geo_dst SELECT readWKT('POLYGON((0 0,1 0,1 1,0 1,0 0))');
SELECT areaSpherical(geom) FROM geo_dst;
response
┌─areaSpherical(geom)────┐
│ -0.0003046096848622019 │
└────────────────────────┘