ST_Polygon
ST_Polygon returns a polygon geometry whose outer ring is the input linestring with the value that was input for the spatial reference system identifier (SRID).
The dimension of the returned geometry is the same as that of the input geometry.
Syntax
ST_Polygon(linestring, srid)
Arguments
- linestring
-
A value of data type
GEOMETRY
or an expression that evaluates to aGEOMETRY
type. The subtype must beLINESTRING
that represents a linestring. The linestring value must be closed. - srid
-
A value of data type
INTEGER
that represents a SRID.
Return type
GEOMETRY
of subtype POLYGON
.
The SRID value of the returned geometry is set to srid.
If linestring or srid is null, then null is returned.
If linestring is not a linestring, then an error is returned.
If linestring is not closed, then an error is returned.
If srid is negative, then an error is returned.
Examples
The following SQL constructs a polygon with an SRID value.
SELECT ST_AsEWKT(ST_Polygon(ST_GeomFromText('LINESTRING(77.29 29.07,77.42 29.26,77.27 29.31,77.29 29.07)'),4356));
st_asewkt
-------------
SRID=4356;POLYGON((77.29 29.07,77.42 29.26,77.27 29.31,77.29 29.07))