Files
observatory-extension/src/pg/sql/40_observatory_utility.sql
2016-04-19 15:39:31 +02:00

154 lines
4.0 KiB
PL/PgSQL

-- Returns the table name with geoms for the given geometry_id
-- TODO probably needs to take in the column_id array to get the relevant
-- table where there is multiple sources for a column from multiple
-- geometries.
CREATE OR REPLACE FUNCTION cdb_observatory._OBS_GeomTable(
geom geometry,
geometry_id text
)
RETURNS TEXT
AS $$
DECLARE
result text;
BEGIN
EXECUTE '
SELECT tablename FROM observatory.OBS_table
WHERE id IN (
SELECT table_id
FROM observatory.OBS_table tab,
observatory.OBS_column_table coltable,
observatory.OBS_column col
WHERE type ILIKE ''geometry''
AND coltable.column_id = col.id
AND coltable.table_id = tab.id
AND col.id = $1
)
'
USING geometry_id, geom
INTO result;
return result;
END;
$$ LANGUAGE plpgsql;
-- A type for use with the OBS_GetColumnData function
CREATE TYPE cdb_observatory.OBS_ColumnData AS (colname text, tablename text, aggregate text);
-- A function that gets the column data for multiple columns
-- Old: OBS_GetColumnData
CREATE OR REPLACE FUNCTION cdb_observatory._OBS_GetColumnData(
geometry_id text,
column_ids text[],
timespan text
)
RETURNS cdb_observatory.OBS_ColumnData[]
AS $$
DECLARE
result cdb_observatory.OBS_ColumnData[];
BEGIN
EXECUTE '
WITH geomref AS (
SELECT t.table_id id
FROM observatory.OBS_column_to_column c2c, observatory.OBS_column_table t
WHERE c2c.reltype = ''geom_ref''
AND c2c.target_id = $1
AND c2c.source_id = t.column_id
),
column_ids as (
select row_number() over () as no, a.column_id as column_id from (select unnest($2) as column_id) a
)
SELECT array_agg(ROW(colname, tablename, aggregate)::cdb_observatory.OBS_ColumnData order by column_ids.no)
FROM column_ids, observatory.OBS_column c, observatory.OBS_column_table ct, observatory.OBS_table t
WHERE column_ids.column_id = c.id
AND c.id = ct.column_id
AND t.id = ct.table_id
AND t.timespan = $3
AND t.id in (SELECT id FROM geomref)
'
USING geometry_id, column_ids, timespan
INTO result;
RETURN result;
END;
$$ LANGUAGE plpgsql;
--Gets the column id for a census variable given a human readable version of it
-- Old: OBS_LOOKUP_CENSUS_HUMAN
CREATE OR REPLACE FUNCTION cdb_observatory._OBS_LookupCensusHuman(
column_names text[],
-- TODO: change variable name table_name to table_id
table_name text DEFAULT '"us.census.acs".extract_block_group_5yr_2013_69b156927c'
)
RETURNS text[] as $$
DECLARE
column_id text;
result text;
BEGIN
EXECUTE format('
WITH col_names AS (
select row_number() over() as no, a.column_name as column_name from(
select unnest($1) as column_name
) a
)
select array_agg(column_id order by col_names.no)
FROM observatory.OBS_column_table,col_names
where colname = col_names.column_name
and table_id = %L limit 1
', table_name)
INTO result
using column_names;
RETURN result;
END
$$ LANGUAGE plpgsql;
--Test point cause Stuart always seems to make random points in the water
CREATE OR REPLACE FUNCTION cdb_observatory._TestPoint()
RETURNS geometry
AS $$
BEGIN
-- new york city
RETURN CDB_LatLng(40.704512, -73.936669);
END;
$$ LANGUAGE plpgsql;
--Test polygon cause Stuart always seems to make random points in the water
-- TODO: remove as it's not used anywhere?
CREATE OR REPLACE FUNCTION cdb_observatory._TestArea()
RETURNS geometry
AS $$
BEGIN
-- Buffer NYC point by 500 meters
RETURN ST_Buffer(cdb_observatory._TestPoint()::geography, 500)::geometry;
END;
$$ LANGUAGE plpgsql;
--Used to expand a column based response to a table based one. Give it the desired
--columns and it will return a partial query for rolling them out to a table.
CREATE OR REPLACE FUNCTION cdb_observatory._OBS_BuildSnapshotQuery(names text[])
RETURNS TEXT
AS $$
DECLARE
q text;
i numeric;
BEGIN
q := 'SELECT ';
FOR i IN 1..array_upper(names,1)
LOOP
q = q || format(' vals[%s] As %I', i, names[i]);
IF i < array_upper(names, 1) THEN
q= q || ',';
END IF;
END LOOP;
RETURN q;
END;
$$ LANGUAGE plpgsql;