ST_AsEWKT — 도형의 WKT(Well-Known Text) 표현식을 SRID 메타데이터와 함께 반환합니다.


text ST_AsEWKT(geometry g1);

text ST_AsEWKT(geometry g1, integer maxdecimaldigits=15);

text ST_AsEWKT(geography g1);

text ST_AsEWKT(geography g1, integer maxdecimaldigits=15);


Returns the Well-Known Text representation of the geometry prefixed with the SRID. The optional maxdecimaldigits argument may be used to reduce the maximum number of decimal digits after floating point used in output (defaults to 15).

To perform the inverse conversion of EWKT representation to PostGIS geometry use ST_GeomFromEWKT.


Using the maxdecimaldigits parameter can cause output geometry to become invalid. To avoid this use ST_ReducePrecision with a suitable gridsize first.


The WKT spec does not include the SRID. To get the OGC WKT format use ST_AsText.


WKT format does not maintain precision so to prevent floating truncation, use ST_AsBinary or ST_AsEWKB format for transport.

Enhanced: 3.1.0 support for optional precision parameter.

개선 사항: 2.0.0 버전부터 지리형, 다면체 표면, 삼각형 및 TIN을 지원하기 시작했습니다.

This function supports 3d and will not drop the z-index.

This method supports Circular Strings and Curves.

This function supports Polyhedral surfaces.

This function supports Triangles and Triangulated Irregular Network Surfaces (TIN).


SELECT ST_AsEWKT('0103000020E61000000100000005000000000000

SRID=4326;POLYGON((0 0,0 1,1 1,1 0,0 0))
(1 row)

SELECT ST_AsEWKT('0108000080030000000000000060E30A4100000000785C0241000000000000F03F0000000018

CIRCULARSTRING(220268 150415 1,220227 150505 2,220227 150406 3)