PostGIS Topology
PostGIS Topology je rozšíření pro PostGIS umožňující topologickou správu vektorových dat v prostředí PostGIS/PostgreSQL.
Více přednášky Úvod do zpracování prostorových dat.
\d urbanarea
Table "public.urbanarea"
Column | Type | Modifiers
--------------+-------------------+-------------------------------------------------------------
ogc_fid | integer | not null default nextval('urbanarea_ogc_fid_seq'::regclass)
wkb_geometry | geometry |
cat | integer |
objectid | integer |
ua | character varying |
name | character varying |
ua_type | character varying |
Indexes:
"urbanarea_pk" PRIMARY KEY, btree (ogc_fid)
"urbanarea_geom_idx" gist (wkb_geometry)
Check constraints:
"enforce_dims_wkb_geometry" CHECK (st_ndims(wkb_geometry) = 2)
"enforce_geotype_wkb_geometry" CHECK (geometrytype(wkb_geometry) = 'POLYGON'::text OR wkb_geometry IS NULL)
"enforce_srid_wkb_geometry" CHECK (st_srid(wkb_geometry) = 900914)
SELECT cat, ua, name, ST_GeometryType(wkb_geometry) from urbanarea limit 5;
cat | ua | name | st_geometrytype -----+-------+------------+----------------- 1 | 29305 | Farmville | ST_Polygon 2 | 92404 | Washington | ST_Polygon 3 | 35380 | Greenville | ST_Polygon 4 | 46315 | La Grange | ST_Polygon 5 | 45397 | Kinston | ST_Polygon
SELECT topology.createtopology('urbanarea');
SELECT * from topology.topology;
id | name | srid | precision ----+-----------+------+----------- 1 | urbanarea | -1 | 0
\dt urbanarea.
List of relations Schema | Name | Type | Owner -----------+-----------+-------+-------- urbanarea | edge_data | table | martin urbanarea | face | table | martin urbanarea | node | table | martin urbanarea | relation | table | martin