Point Constructors

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﻿ POINT constructors use geospatial data to create a POINT object. 
ST_CENTROID 
Returns a POINT that is the geographic center of mass of a specified geospatial object. 
The geographic center of mass is calculated by taking the average of all points on a three-dimensional sphere, projecting the resultant point onto the sphere, and converting it back to latitude and longitude coordinates.
Syntax
SQL
ST_CENTROID( geo [, use_spheroid ] )
ST_CENTROID( geo [, use_spheroid ] )
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Argument
Data Type
Description
geo
POINT, LINESTRING, or POLYGON
A geospatial object that the function analyzes to compute its geometric center. 
use_spheroid
BOOLEAN
Optional. 
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If this argument is TRUE, the function computes the centroid using a spheroid model instead of a spherical model. 
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If you do not specify this value, the value defaults to FALSE. 
Example
SQL
SELECT ST_CENTROID(ST_POLYGON('POLYGON((1 1, 2 1, 2 2, 1 1))'));
SELECT ST_CENTROID(ST_POLYGON('POLYGON((1 1, 2 1, 2 2, 1 1))'));
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Output: POINT(1.66 1.33) 
ST_GEOGPOINT
Alias for ST_POLYGON(ST_LINESTRING(ARRAY(ST_POINT(lon, lat)))).
Creates and returns a POLYGON geography with a single point, defined by the longitude and latitude specified for the function. 
Syntax
SQL
ST_GEOGPOINT(lon, lat)
ST_GEOGPOINT(lon, lat)
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Argument
Data Type
Description
lon
DOUBLE
A longitude coordinate to be used to create a POLYGON with a single point. 
lat
DOUBLE
A latitude coordinate to be used to create a POLYGON with a single point. 
Example
SQL
SELECT ST_GEOGPOINT(41.882548,-87.63922);
SELECT ST_GEOGPOINT(41.882548,-87.63922);
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Output: POLYGON((41.882548 -87.63922))
ST_MAKEPOINT
Alias for ST_POINT﻿. 
ST_POINT
Creates a POINT from the specified input arguments. 
ST_POINT(binary)
Alias for ST_POINTFROMWKB.
Creates a POINT from the specified BINARY value, which must represent a point in WKB format. 
Syntax
SQL
ST_POINT(binary)
ST_POINT(binary)
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Argument
Data Type
Description
binary
BINARY
A binary value in WKB format that represents a POINT. 
Example
SQL
SELECT ST_POINT(BINARY('0x0101000000000000000000f03f0000000000000040'));
SELECT ST_POINT(BINARY('0x0101000000000000000000f03f0000000000000040'));
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Output: POINT(1 2)
ST_POINT(char)
Creates a POINT from a CHAR value that represents a point in WKT format. 
Syntax
SQL
ST_POINT(char)
ST_POINT(char)
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Argument
Data Type
Description
char
CHAR
A CHAR that represents a POINT in WKT format. 
Example
SQL
SELECT ST_POINT('POINT(1 2)');
SELECT ST_POINT('POINT(1 2)');
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Output: POINT(1 2)
ST_POINT(lon, lat)
Creates a POINT defined with the values provided for the longitude and latitude coordinates. 
Syntax
SQL
ST_POINT(lon, lat)
ST_POINT(lon, lat)
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Argument
Data Type
Description
lon
DOUBLE
A DOUBLE value that represents a longitude coordinate. 
lat
DOUBLE
A DOUBLE value that represents a latitude coordinate. 
Example
SQL
SELECT ST_POINT(87.6386, 41.8843);
SELECT ST_POINT(87.6386, 41.8843);
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Output: POINT(87.6386 41.8843)
ST_POINTFROMEWKT
Alias for ST_POINT﻿.
Creates a POINT using an EWKT-formatted CHAR as an input argument. 
Syntax
SQL
ST_POINTFROMEWKT(srid_char)
ST_POINTFROMEWKT(srid_char)
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Argument
Data Type
Description
srid_char
CHAR
A string that includes an SRID value and an EWKT-formatted value that represents a POINT.
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Separate the values in the string by a semicolon using this format: 
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'SRID = value; point_value'
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The input string must include the SRID = value; component. However, the database ignores this component as all 
﻿ geography types are SRID = 4326.
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Example
SQL
SELECT ST_POINTFROMEWKT('SRID=4326;POINT(1 2)');
SELECT ST_POINTFROMEWKT('SRID=4326;POINT(1 2)');
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Output: POINT(1 2)
ST_POINTFROMGEOJSON
Creates a POINT represented by the specified GeoJSON value as an input argument. A second optional BOOLEAN argument determines if the specified GeoJSON should be converted from a planar to a geodesic representation. 
If you specify a NULL value for either argument, the function returns NULL. 
Syntax
SQL
ST_POINTFROMGEOJSON(geojson [, geodesic ] )
ST_POINTFROMGEOJSON(geojson [, geodesic ] )
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Argument
Data Type
Description
geo_json
STRING
A string of a GeoJSON. 
Valid GeoJSON formats follow IETF standards, which you can generate by using the ST_ASGEOJSON﻿  function.
If you specify an invalid GeoJSON, the behavior of the function is undefined. The function returns NULL if any argument is NULL.
geodesic
BOOLEAN
Optional. 
If you set this argument to TRUE, the specified GeoJSON is converted from a planar to a geodesic representation. This has no effect on POINT geospatial objects.
If you do not specify this value, defaults to FALSE. 
Examples
In this example, the function is capturing a POINT from an empty GeoJSON representation. 
SQL
SELECT ST_POINTFROMGEOJSON('{"type":"Point","coordinates":[]}',false);
SELECT ST_POINTFROMGEOJSON('{"type":"Point","coordinates":[]}',false);
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Output:  POINT EMPTY
In this example, the function is capturing a POINT from a GeoJSON representation. 
SQL
SELECT ST_POINTFROMGEOJSON('{"type":"Point","coordinates":[1,1]}',false);
SELECT ST_POINTFROMGEOJSON('{"type":"Point","coordinates":[1,1]}',false);
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Output:  POINT(1 1)
ST_POINTFROMGEOHASH
Creates a POINT represented by the specified geohash. 
Syntax
SQL
ST_POINTFROMGEOHASH(geohash)
ST_POINTFROMGEOHASH(geohash)
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Argument
Data Type
Description
geohash
STRING
A string of a valid geohash. 
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Valid geohashes contain only the characters 0123456789bcdefghjkmnpqrstuvwxyz.
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If you specify an invalid geohash, the function throws an INVALID_ARGUMENT error. The function returns NULL if this argument is NULL. 
Examples
SQL
SELECT ST_POINTFROMGEOHASH('c0w3hf1s70w3hf1s70w3');
SELECT ST_POINTFROMGEOHASH('c0w3hf1s70w3hf1s70w3');
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Output: POINT(-126.00000000000003 48.00000000000007)
SQL
SELECT ST_POINTFROMGEOHASH('kzn21');
SELECT ST_POINTFROMGEOHASH('kzn21');
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Output: POINT(42.60498046875 -5.60302734375)
ST_POINTFROMTEXT
Alias for ST_POINT(char)﻿.
ST_POINTFROMWKB
Alias for ST_POINT(binary)﻿.
Related Links
﻿Geospatial Data Types﻿﻿
﻿Conversion Functions﻿﻿

Argument	Data Type	Description
geo	POINT, LINESTRING, or POLYGON	A geospatial object that the function analyzes to compute its geometric center.
use_spheroid	BOOLEAN	Optional. If this argument is TRUE, the function computes the centroid using a spheroid model instead of a spherical model. If you do not specify this value, the value defaults to FALSE.

Argument	Data Type	Description
lon	DOUBLE	A longitude coordinate to be used to create a POLYGON with a single point.
lat	DOUBLE	A latitude coordinate to be used to create a POLYGON with a single point.

Argument	Data Type	Description
binary	BINARY	A binary value in WKB format that represents a POINT.

Argument	Data Type	Description
char	CHAR	A CHAR that represents a POINT in WKT format.

Argument	Data Type	Description
lon	DOUBLE	A DOUBLE value that represents a longitude coordinate.
lat	DOUBLE	A DOUBLE value that represents a latitude coordinate.

Argument	Data Type	Description
srid_char	CHAR	A string that includes an SRID value and an EWKT-formatted value that represents a POINT. Separate the values in the string by a semicolon using this format: 'SRID = value; point_value' The input string must include the SRID = value; component. However, the database ignores this component as all geography types are SRID = 4326.

Argument	Data Type	Description
geo_json	STRING	A string of a GeoJSON. Valid GeoJSON formats follow IETF standards, which you can generate by using the ST_ASGEOJSON function. If you specify an invalid GeoJSON, the behavior of the function is undefined. The function returns NULL if any argument is NULL.
geodesic	BOOLEAN	Optional. If you set this argument to TRUE, the specified GeoJSON is converted from a planar to a geodesic representation. This has no effect on POINT geospatial objects. If you do not specify this value, defaults to FALSE.

Argument	Data Type	Description
geohash	STRING	A string of a valid geohash. Valid geohashes contain only the characters 0123456789bcdefghjkmnpqrstuvwxyz. If you specify an invalid geohash, the function throws an INVALID_ARGUMENT error. The function returns NULL if this argument is NULL.

Updated 22 May 2024

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Linestring Functions

Polygon Constructors