Polygon

An object identified by a set of closed linestrings. A polygon can have one or more holes, as defined by interior boundaries, but all points must be connected. Two examples of polygons are:

Inclusive and exclusive polygons

Polygons that include their points in clockwise order include all space inside the perimeter of the polygon and exclude all space outside that perimeter. Polygons that include their points in counterclockwise order exclude all space inside the perimeter and include all space outside that perimeter.

Examples

The following example uses the GEOMETRY type to create a table, use copy to load a polygon into the table, and then queries the table to view the polygon:

=> CREATE TABLE polygon_geom (gid int, geom GEOMETRY(1000));
CREATE TABLE
=> COPY polygon_geom(gid, gx filler LONG VARCHAR, geom AS ST_GeomFromText(gx)) FROM stdin delimiter '|';
Enter data to be copied followed by a newline.
End with a backslash and a period on a line by itself.
>>1|POLYGON(( 2 6, 2 9, 6 9, 7 7, 4 6, 2 6))
>>\.
=> SELECT gid, ST_AsText(geom) FROM polygon_geom;
 gid |                 ST_AsText
-----+------------------------------------------
   1 | POLYGON((2 6, 2 9, 6 9, 7 7, 4 6, 2 6))
(1 row)

The following example uses the GEOGRAPHY type to create a table, use copy to load a polygon into the table, and then queries the table to view the polygon:

=> CREATE TABLE polygon_geog (gid int, geog GEOGRAPHY(1000));
CREATE TABLE
=> COPY polygon_geog(gid, gx filler LONG VARCHAR, geog AS ST_GeographyFromText(gx)) FROM stdin delimiter '|';
Enter data to be copied followed by a newline.
End with a backslash and a period on a line by itself.
>>1|POLYGON((42.1 71, 41.4 70, 41.3 72.9, 44.47 73.21, 42.99 71.46, 42.1 71))
>>\.
=> SELECT gid, ST_AsText(geog) FROM polygon_geog;
 gid |                                ST_AsText
-----+---------------------------------------------------------------------------
   1 | POLYGON((42.1 71, 41.4 70, 41.3 72.9, 44.47 73.21, 42.99 71.46, 42.1 71))
(1 row)