Beschreibung

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.

Erweiterung: Mit 2.0.0 wurde die Unterstützung für den geographischen Datentyp, polyedrische Oberflächen, Dreiecke und TIN eingeführt.

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).

Beispiele

SELECT ST_AsEWKT('0103000020E61000000100000005000000000000
                        000000000000000000000000000000000000000000000000000000
                        F03F000000000000F03F000000000000F03F000000000000F03
                        F000000000000000000000000000000000000000000000000'::geometry);

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

SELECT ST_AsEWKT('0108000080030000000000000060E30A4100000000785C0241000000000000F03F0000000018
E20A4100000000485F024100000000000000400000000018
E20A4100000000305C02410000000000000840')

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

Siehe auch

ST_AsBinary, ST_AsEWKB, ST_AsText, ST_GeomFromEWKT