Name

ST_Polygon — Creates a Polygon from a LineString with a specified SRID.

Synopsis

geometry ST_Polygon(geometry lineString, integer srid);

Description

Returns a polygon built from the given LineString and sets the spatial reference system from the srid.

ST_Polygon is similar to ST_MakePolygon Variant 1 with the addition of setting the SRID.

To create polygons with holes use ST_MakePolygon Variant 2 and then ST_SetSRID.

[Note]

This function does not accept MultiLineStrings. Use ST_LineMerge to generate a LineString, or ST_Dump to extract LineStrings.

This method implements the OGC Simple Features Implementation Specification for SQL 1.1.

This method implements the SQL/MM specification. SQL-MM 3: 8.3.2

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

Examples

Create a 2D polygon.

Code
SELECT ST_Polygon('LINESTRING(75 29,77 29,77 31,75 31,75 29)'::geometry, 4326);
Output
POLYGON((75 29,77 29,77 31,75 31,75 29))
Figure
Geometry figure for visual-st-polygon-01

Create a 3D polygon.

Code
SELECT ST_Polygon('LINESTRING(75 29 1,77 29 2,77 31 2,75 31 1,75 29 1)'::geometry, 4326);
Output
SRID=4326;POLYGON((75 29 1,77 29 2,77 31 2,75 31 1,75 29 1))
Figure
Geometry figure for visual-st-polygon-02