ST_PolygonFromText
Name
ST_PolygonFromText — Makes a Geometry from WKT with the given SRID. If SRID is not given, it defaults to 0.
Synopsis
    
     geometry
     
      ST_PolygonFromText
     
     (
    
    text
    
     WKT
    
    
     )
    
    ;
   
    
     geometry
     
      ST_PolygonFromText
     
     (
    
    text
    
     WKT
    
    , integer
    
     srid
    
    
     )
    
    ;
   
Description
Makes a Geometry from WKT with the given SRID. If SRID is not given, it defaults to 0. Returns null if WKT is not a polygon.
OGC SPEC 3.2.6.2 - option SRID is from the conformance suite
       
      | 
     |
| 
       If you are absolutely sure all your WKT geometries are polygons, don't use this function. It is slower than ST_GeomFromText since it adds an additional validation step.  | 
    
   
    
   
   This method implements the
   
    OpenGIS Simple Features
 Implementation Specification for SQL 1.1.
   
   s3.2.6.2
  
   
    
   
   This method implements the SQL/MM specification. SQL-MM 3: 8.3.6
  
Examples
SELECT ST_PolygonFromText('POLYGON((-71.1776585052917 42.3902909739571,-71.1776820268866 42.3903701743239,
-71.1776063012595 42.3903825660754,-71.1775826583081 42.3903033653531,-71.1776585052917 42.3902909739571))');
st_polygonfromtext
------------------
010300000001000000050000006...
SELECT ST_PolygonFromText('POINT(1 2)') IS NULL as point_is_notpoly;
point_is_not_poly
----------
t