From 1a19e338770458a6b52a639a37d706d8915b4809 Mon Sep 17 00:00:00 2001 From: Andy Eschbacher Date: Thu, 28 Apr 2016 11:14:15 -0700 Subject: [PATCH] adding boundaries by bbox functions --- src/pg/sql/44_observatory_geometries.sql | 175 +++++++++++++++++++++++ 1 file changed, 175 insertions(+) diff --git a/src/pg/sql/44_observatory_geometries.sql b/src/pg/sql/44_observatory_geometries.sql index 59cec2c..48af9be 100644 --- a/src/pg/sql/44_observatory_geometries.sql +++ b/src/pg/sql/44_observatory_geometries.sql @@ -242,3 +242,178 @@ BEGIN END; $$ LANGUAGE plpgsql; + + +-- OBS_GetBoundariesByBBox +-- +-- Given a bounding box (or a polygon), and it's geometry level (see +-- OBS_ListGeomColumns() for all available boundary ids), give back the +-- boundaries that are contained within the bounding box polygon and the +-- associated geometry ids + +-- Inputs: +-- geom geometry: bounding box (or polygon) of the region of interest +-- boundary_id text: source id of boundaries (e.g., us.census.tiger.county) +-- see function OBS_ListGeomColumns for all avaiable +-- boundary ids +-- time_span text: time span that the geometries were collected (optional) +-- +-- Output: +-- table with the following columns +-- boundary geometry: geometry boundary that is contained within the input +-- bounding box at the requested geometry level +-- with boundary_id, and time_span +-- geom_refs text: geometry identifiers (e.g., geoid for the US Census) +-- + +CREATE OR REPLACE FUNCTION cdb_observatory.OBS_GetBoundariesByBBox( + geom geometry(Geometry, 4326), + boundary_id text, + time_span text DEFAULT NULL) +RETURNS TABLE(boundary geometry, geom_refs text) +AS $$ +DECLARE + boundary geometry(Geometry, 4326); + geom_colname text; + geoid_colname text; + target_table text; +BEGIN + +-- TODO: add timespan in search +EXECUTE +format( + $string$ + SELECT geoid_ct.colname As geoid_colname, + tablename, + geom_ct.colname As geom_colname + FROM observatory.obs_column_table As geoid_ct, + observatory.obs_table As geom_t, + observatory.obs_column_table As geom_ct, + observatory.obs_column As geom_c + WHERE geoid_ct.column_id + IN ( + SELECT source_id + FROM observatory.obs_column_to_column + WHERE reltype = 'geom_ref' + AND target_id = '%s' + ) + AND geoid_ct.table_id = geom_t.id and + geom_t.id = geom_ct.table_id and + geom_ct.column_id = geom_c.id and + geom_c.type ILIKE 'geometry' + $string$, boundary_id +) INTO geoid_colname, target_table, geom_colname; + + -- if not a point, raise error + IF ST_GeometryType(geom) NOT IN ('ST_Polygon', 'ST_MultiPolygon') + THEN + RAISE EXCEPTION 'Invalid geometry type (%), expecting ''ST_MultiPolygon'' or ''ST_Polygon''', ST_GeometryType(geom); + END IF; + + -- if no tables are found, raise notice and return null + IF target_table IS NULL + THEN + RAISE NOTICE 'No boundaries found for bounding box ''%'' in ''%''', ST_AsText(geom), boundary_id; + RETURN QUERY SELECT NULL::geometry, NULL::text; + END IF; + + RAISE NOTICE 'target_table: %', target_table; + + -- return first boundary in intersections + RETURN QUERY + EXECUTE format( + 'SELECT t.%s, t.%s + FROM observatory.%s As t + WHERE ST_Contains($1, t.the_geom) + ', geom_colname, geoid_colname, target_table) + USING geom; + +END; +$$ LANGUAGE plpgsql; + +-- OBS_GetPointsByBBox +-- +-- Given a bounding box (or a polygon), and it's geometry level (see +-- OBS_ListGeomColumns() for all available boundary ids), give back a point +-- which lies in a boundary from the requested geometry level that is contained +-- within the bounding box polygon and the associated geometry ids +-- +-- Inputs: +-- geom geometry: bounding box (or polygon) of the region of interest +-- boundary_id text: source id of boundaries (e.g., us.census.tiger.county) +-- see function OBS_ListGeomColumns for all avaiable +-- boundary ids +-- time_span text: time span that the geometries were collected (optional) +-- +-- Output: +-- table with the following columns +-- boundary geometry: point that lies on a boundary that is contained within +-- the input bounding box at the requested geometry +-- level with boundary_id, and time_span +-- geom_refs text: geometry identifiers (e.g., geoid for the US Census) +-- + +CREATE OR REPLACE FUNCTION cdb_observatory.OBS_GetPointsByBBox( + geom geometry(Geometry, 4326), + boundary_id text, + time_span text DEFAULT NULL) +RETURNS TABLE(boundary geometry, geom_refs text) +AS $$ +DECLARE + boundary geometry(Geometry, 4326); + geom_colname text; + geoid_colname text; + target_table text; +BEGIN + +-- TODO: add timespan in search +EXECUTE +format( + $string$ + SELECT geoid_ct.colname As geoid_colname, + tablename, + geom_ct.colname As geom_colname + FROM observatory.obs_column_table As geoid_ct, + observatory.obs_table As geom_t, + observatory.obs_column_table As geom_ct, + observatory.obs_column As geom_c + WHERE geoid_ct.column_id + IN ( + SELECT source_id + FROM observatory.obs_column_to_column + WHERE reltype = 'geom_ref' + AND target_id = '%s' + ) + AND geoid_ct.table_id = geom_t.id and + geom_t.id = geom_ct.table_id and + geom_ct.column_id = geom_c.id and + geom_c.type ILIKE 'geometry' + $string$, boundary_id +) INTO geoid_colname, target_table, geom_colname; + + -- if not a point, raise error + IF ST_GeometryType(geom) NOT IN ('ST_Polygon', 'ST_MultiPolygon') + THEN + RAISE EXCEPTION 'Invalid geometry type (%), expecting ''ST_MultiPolygon'' or ''ST_Polygon''', ST_GeometryType(geom); + END IF; + + -- if no tables are found, raise notice and return null + IF target_table IS NULL + THEN + RAISE NOTICE 'No boundaries found for bounding box ''%'' in ''%''', ST_AsText(geom), boundary_id; + RETURN QUERY SELECT NULL::geometry, NULL::text; + END IF; + + RAISE NOTICE 'target_table: %', target_table; + + -- return first boundary in intersections + RETURN QUERY + EXECUTE format( + 'SELECT ST_PointOnSurface(t.%s) As %s, t.%s + FROM observatory.%s As t + WHERE ST_Contains($1, t.the_geom) + ', geom_colname, geom_colname, geoid_colname, target_table) + USING geom; + +END; +$$ LANGUAGE plpgsql;