ST_Polygon — Returns a polygon built from the specified linestring and SRID.
geometry ST_Polygon(geometry  aLineString, integer  srid);
Returns a polygon built from the specified linestring and SRID.
| ![[Note]](images/note.png) | |
| ST_Polygon is similar to first version oST_MakePolygon except it also sets the spatial ref sys (SRID) of the polygon. Will not work with MULTILINESTRINGS so use LineMerge to merge multilines. Also does not create polygons with holes. Use ST_MakePolygon for that. | 
 This method implements the OpenGIS Simple Features
 Implementation Specification for SQL 1.1.
 This method implements the OpenGIS Simple Features
 Implementation Specification for SQL 1.1.
 This method implements the SQL/MM specification. SQL-MM 3: 8.3.2
 This method implements the SQL/MM specification. SQL-MM 3: 8.3.2
 This function supports 3d and will not drop the z-index.
 This function supports 3d and will not drop the z-index.
--a 2d polygon
SELECT ST_Polygon(ST_GeomFromText('LINESTRING(75.15 29.53,77 29,77.6 29.5, 75.15 29.53)'), 4326);
--result--
POLYGON((75.15 29.53,77 29,77.6 29.5,75.15 29.53))
--a 3d polygon
SELECT ST_AsEWKT(ST_Polygon(ST_GeomFromEWKT('LINESTRING(75.15 29.53 1,77 29 1,77.6 29.5 1, 75.15 29.53 1)'), 4326));
result
------
SRID=4326;POLYGON((75.15 29.53 1,77 29 1,77.6 29.5 1,75.15 29.53 1))