ST_GeogFromText

ST_GeogFromText constructs a geography object from a well-known text (WKT) or extended well-known text (EWKT) representation of an input geography.

Syntax

ST_GeogFromText(wkt_string)

Arguments

wkt_string

A value of data type VARCHAR that is a WKT or EWKT representation of a geography.

Return type

GEOGRAPHY

If the SRID value is set to the provided value in the input. If SRID is not provided, it is set to 4326.

If wkt_string is null, then null is returned.

If wkt_string is not valid, then an error is returned.

Examples

The following SQL constructs a polygon from a geography object with an SRID value.

SELECT ST_AsEWKT(ST_GeogFromText('SRID=4324;POLYGON((0 0,0 1,1 1,10 10,1 0,0 0))'));

  st_asewkt
------------------------------------------------
 SRID=4324;POLYGON((0 0,0 1,1 1,10 10,1 0,0 0))
 

The following SQL constructs a polygon from a geography object. The SRID value is set to 4326.

SELECT ST_AsEWKT(ST_GeogFromText('POLYGON((0 0,0 1,1 1,10 10,1 0,0 0))'));

 st_asewkt
------------------------------------------------
 SRID=4326;POLYGON((0 0,0 1,1 1,10 10,1 0,0 0))