GanosBaseジオメトリは、PostgreSQLの空間ジオメトリ拡張です。 GanosBase GeometryはOpenGIS仕様に準拠しており、PostgreSQLが2D (X、Y) 、3D (X、Y、Z) 、および4D (X、Y、Z、M) 空間ジオメトリデータを保存および管理できます。 GanosBaseジオメトリには、空間ジオメトリオブジェクト、インデックス、関数、演算子などのさまざまな機能もあります。
概要
ジオメトリモデルはPostGIS操作と完全に互換性があり、既存のアプリケーションをスムーズに移行できます。
入門ガイド
拡張機能を作成します。
-- Create a geometry extension. Create extension ganos_geometry with schema public cascade;重要作成しない 同じスキーマ内のGanosBase拡張またはPostGIS拡張。 それ以外の場合、エラーメッセージ
error: table "spatial_ref_sys" is not a member of the extension being createdが表示されます。を作成するとき GanosBaseまたはPostGIS拡張では、
spatial_ref_sysという名前のテーブルが自動的に作成されます。 を作成する場合は、 GanosBase拡張とPostGIS拡張が同じスキーマ内にある場合、テーブルの競合が発生します。 作成することを推奨します GanosBaseと異なるスキーマのPostGIS拡張機能。 を作成する前に、PostGIS拡張機能を削除できます。 GanosBase拡張。ジオメトリテーブルを作成します。
-- Method 1: Create a table that contains a geometry field. CREATE TABLE ROADS ( ID int4, ROAD_NAME varchar(25), geom geometry(LINESTRING,3857) ); -- Method 2: Create a regular table and then add a geometry field to the table. CREATE TABLE ROADS (ID int4, ROAD_NAME varchar(25)); SELECT AddGeometryColumn( 'roads', 'geom', 3857, 'LINESTRING', 2);ジオメトリ制約を追加します。
ALTER TABLE ROADS ADD CONSTRAINT geometry_valid_check CHECK (ST_IsValid(geom));ジオメトリデータをインポートします。
INSERT INTO roads (id, geom, road_name) VALUES (1,ST_GeomFromText('LINESTRING(191232 243118,191108 243242)',3857),'North Fifth-Ring Road'); INSERT INTO roads (id, geom, road_name) VALUES (2,ST_GeomFromText('LINESTRING(189141 244158,189265 244817)',3857),'East Fifth-Ring Road'); INSERT INTO roads (id, geom, road_name) VALUES (3,ST_GeomFromText('LINESTRING(192783 228138,192612 229814)',3857),'South Fifth-Ring Road'); INSERT INTO roads (id, geom, road_name) VALUES (4,ST_GeomFromText('LINESTRING(189412 252431,189631 259122)',3857),'West Fifth-Ring Road'); INSERT INTO roads (id, geom, road_name) VALUES (5,ST_GeomFromText('LINESTRING(190131 224148,190871 228134)',3857),'East Chang'an Avenue'); INSERT INTO roads (id, geom, road_name) VALUES (6,ST_GeomFromText('LINESTRING(198231 263418,198213 268322)',3857),'West Chang'an Avenue');ジオメトリオブジェクト情報を照会します。
SELECT id, ST_AsText(geom) AS geom, road_name FROM roads; -------------------------------- id | geom | road_name --------+-----------------------------------------+----------- 1 | LINESTRING(191232 243118,191108 243242) | North Fifth-Ring Road 2 | LINESTRING(189141 244158,189265 244817) | East Fifth-Ring Road 3 | LINESTRING(192783 228138,192612 229814) | South Fifth-Ring Road 4 | LINESTRING(189412 252431,189631 259122) | West Fifth-Ring Road 5 | LINESTRING(190131 224148,190871 228134) | East Chang'an Avenue 6 | LINESTRING(198231 263418,198213 268322) | West Chang'an Avenue (6 rows)インデックスを作成します。
-- Create a GiST index. CREATE INDEX [indexname] ON [tablename] USING GIST ( [geometryfield] ); CREATE INDEX [indexname] ON [tablename] USING GIST ([geometryfield] gist_geometry_ops_nd); VACUUM ANALYZE [table_name] [(column_name)]; -- Example: Create INDEX sp_geom_index ON ROADS USING GIST(geom); VACUUM ANALYZE ROADS (geom); -- Create a block range index (BRIN). CREATE INDEX [indexname] ON [tablename] USING BRIN ( [geometryfield] ); CREATE INDEX [indexname] ON [tablename] USING BRIN ([geometryfield] brin_geometry_inclusion_ops_3d); CREATE INDEX [indexname] ON [tablename] USING BRIN ([geometryfield] brin_geometry_inclusion_ops_4d); -- Create a BRIN index that has a specified range. CREATE INDEX [indexname] ON [tablename] USING BRIN ( [geometryfield] ) WITH (pages_per_range = [number]);ジオメトリオブジェクトにアクセスします。
-- Determine whether a spatial geometry object consists of only simple elements. SELECT ST_IsSimple(ST_GeomFromText('POLYGON((1 2, 3 4, 5 6, 1 2))')); st_issimple ------------- t (1 row) SELECT ST_IsSimple(ST_GeomFromText('LINESTRING(1 1,2 2,2 3.5,1 3,1 2,2 1)')); st_issimple ------------- f (1 row) -- Query the largest city that has traffic circles in the terrain. SELECT gid, name, ST_Area(the_geom) AS area FROM bc_municipality WHERE ST_NRings(the_geom) > 1 ORDER BY area DESC LIMIT 1; gid | name | area -----+--------------+------------------ 12 | Anning | 257374619.430216 (1 row)空間データを測定および分析し、空間関係を特定する。
-- Create the bc_roads table. Create table bc_roads (gid serial, name varchar, the_geom geometry); -- Create the bc_municipality table. Create table bc_municipality(gid serial, code integer, name varchar, the_geom geometry); -- Calculate the length. SELECT sum(ST_Length(the_geom))/1000 AS km_roads FROM bc_roads; km_roads ------------------ 70842.1243039643 (1 row) -- Calculate the area. SELECT ST_Area(the_geom)/10000 AS hectares FROM bc_municipality WHERE name = 'PRINCE GEORGE'; hectares ------------------ 32657.9103824927 (1 row) -- Use the ST_Contains function. SELECT m.name, sum(ST_Length(r.the_geom))/1000 as roads_km FROM bc_roads AS r, bc_municipality AS m WHERE ST_Contains(m.the_geom,r.the_geom) GROUP BY m.name ORDER BY roads_km; name | roads_km ----------------------------+------------------ SURREY | 1539.47553551242 VANCOUVER | 1450.33093486576 LANGLEY DISTRICT | 833.793392535662 BURNABY | 773.769091404338 PRINCE GEORGE | 694.37554369147 -- Use the ST_Covers function. SELECT ST_Covers(smallc,smallc) As smallinsmall, ST_Covers(smallc, bigc) As smallcoversbig, ST_Covers(bigc, ST_ExteriorRing(bigc)) As bigcoversexterior, ST_Contains(bigc, ST_ExteriorRing(bigc)) As bigcontainsexterior FROM (SELECT ST_Buffer(ST_GeomFromText('POINT(1 2)'), 10) As smallc, ST_Buffer(ST_GeomFromText('POINT(1 2)'), 20) As bigc) As foo; --Result smallinsmall | smallcoversbig | bigcoversexterior | bigcontainsexterior --------------+----------------+-------------------+--------------------- t | f | t | f (1 row) -- Use the ST_Disjoint function. SELECT ST_Disjoint('POINT(0 0)'::geometry, 'LINESTRING ( 2 0, 0 2 )'::geometry); st_disjoint --------------- t (1 row) SELECT ST_Disjoint('POINT(0 0)'::geometry, 'LINESTRING ( 0 0, 0 2 )'::geometry); st_disjoint --------------- f (1 row) -- Use the ST_Overlaps function. SELECT ST_Overlaps(a,b) As a_overlap_b, ST_Crosses(a,b) As a_crosses_b, ST_Intersects(a, b) As a_intersects_b, ST_Contains(b,a) As b_contains_a FROM (SELECT ST_GeomFromText('POINT(1 0.5)') As a, ST_GeomFromText('LINESTRING(1 0, 1 1, 3 5)') As b) As foo a_overlap_b | a_crosses_b | a_intersects_b | b_contains_a ------------+-------------+----------------+-------------- f | f | t | t -- Use the ST_Relate function. SELECT ST_Relate(ST_GeometryFromText('POINT(1 2)'), ST_Buffer(ST_GeometryFromText('POINT(1 2)'),2), '0FFFFF212'); st_relate ----------- t -- Use the ST_Touches function. SELECT ST_Touches('LINESTRING(0 0, 1 1, 0 2)'::geometry, 'POINT(1 1)'::geometry); st_touches ------------ f (1 row) SELECT ST_Touches('LINESTRING(0 0, 1 1, 0 2)'::geometry, 'POINT(0 2)'::geometry); st_touches ------------ t (1 row) -- Use the ST_Within function. SELECT ST_Within(smallc,smallc) As smallinsmall, ST_Within(smallc, bigc) As smallinbig, ST_Within(bigc,smallc) As biginsmall, ST_Within(ST_Union(smallc, bigc), bigc) as unioninbig, ST_Within(bigc, ST_Union(smallc, bigc)) as biginunion, ST_Equals(bigc, ST_Union(smallc, bigc)) as bigisunion FROM ( SELECT ST_Buffer(ST_GeomFromText('POINT(50 50)'), 20) As smallc, ST_Buffer(ST_GeomFromText('POINT(50 50)'), 40) As bigc) As foo; --Result smallinsmall | smallinbig | biginsmall | unioninbig | biginunion | bigisunion --------------+------------+------------+------------+------------+------------ t | t | f | t | t | t (1 row)拡張機能を削除します。
Drop extension ganos_geometry cascade;
SQL リファレンス
詳細については、「公式PostGISリファレンス」をご参照ください。