80 lines
2.9 KiB
PL/PgSQL
80 lines
2.9 KiB
PL/PgSQL
--
|
|
--
|
|
-- OBS_GetMeasure
|
|
--
|
|
--
|
|
|
|
CREATE OR REPLACE FUNCTION cdb_observatory._OBS_GetMeasureResultMetadata(params json)
|
|
RETURNS cdb_observatory.ds_return_metadata
|
|
AS $$
|
|
DECLARE
|
|
colnames text[]; -- Array to store the name of the measures to be returned
|
|
coltypes text[]; -- Array to store the type of the measures to be returned
|
|
requested_measures text[];
|
|
measure_id text;
|
|
BEGIN
|
|
-- By definition, all the measure results for the OBS_GetMeasure API are numeric values
|
|
SELECT ARRAY(SELECT json_array_elements_text(params->'measure_id'))::text[] INTO requested_measures;
|
|
|
|
FOREACH measure_id IN ARRAY requested_measures
|
|
LOOP
|
|
SELECT array_append(colnames, measure_id) INTO colnames;
|
|
SELECT array_append(coltypes, 'numeric'::text) INTO coltypes;
|
|
END LOOP;
|
|
|
|
RETURN (colnames::text[], coltypes::text[]);
|
|
END;
|
|
$$ LANGUAGE plpgsql;
|
|
|
|
CREATE OR REPLACE FUNCTION cdb_observatory._OBS_GetMeasureQuery(table_schema text, table_name text, params json)
|
|
RETURNS text
|
|
AS $$
|
|
DECLARE
|
|
data_query text;
|
|
measure_ids_arr text[];
|
|
measure_id text;
|
|
measures_list text;
|
|
measures_query text;
|
|
normalize text;
|
|
boundary_id text;
|
|
time_span text;
|
|
geom_table_name text;
|
|
data_table_name text;
|
|
BEGIN
|
|
measures_query := '';
|
|
-- SELECT table_name from obs_meta WHERE boundary_id = {bound} AND [...] INTO geom_table_name
|
|
geom_table_name := 'observatory.obs_c6fb99c47d61289fbb8e561ff7773799d3fcc308';
|
|
-- SELECT table_name from obs_meta WHERE time_span = {time} AND [...] INTO data_table_name
|
|
data_table_name := 'observatory.obs_1a098da56badf5f32e336002b0a81708c40d29cd';
|
|
|
|
-- Get measure_ids array from JSON
|
|
SELECT ARRAY(SELECT json_array_elements_text(params->'measure_id'))::text[] INTO measure_ids_arr;
|
|
|
|
-- Get a comma-separated list of measures ("total_pop, over_16_pop") to be used in SELECTs
|
|
SELECT array_to_string(measure_ids_arr, ',') INTO measures_list;
|
|
|
|
FOREACH measure_id IN ARRAY measure_ids_arr
|
|
LOOP
|
|
-- Build query to compute each value and normalize
|
|
-- Assumes the default normalization method, the normalize parameter given in the JSON
|
|
-- should be checked in order to build the final query
|
|
SELECT measures_query || ' sum(' || measure_id || '/fraction)::numeric as ' || measure_id || ', ' INTO measures_query;
|
|
END LOOP;
|
|
|
|
-- Data query should select the measures and the cartodb_id of the user table, in that order.
|
|
data_query := '(WITH _areas AS(SELECT ST_Area(a.the_geom::geography)'
|
|
|| '/ (1000 * 1000) as fraction, a.geoid, b.cartodb_id FROM '
|
|
|| geom_table_name || ' as a, '
|
|
|| table_schema || '.' || table_name || ' AS b '
|
|
|| 'WHERE b.the_geom && a.the_geom ), values AS (SELECT geoid, '
|
|
|| measures_list
|
|
|| ' FROM ' || data_table_name || ' ) '
|
|
|| 'SELECT '
|
|
|| measures_query
|
|
|| ' cartodb_id::int FROM _areas, values '
|
|
|| 'WHERE values.geoid = _areas.geoid GROUP BY cartodb_id);';
|
|
RETURN data_query;
|
|
END;
|
|
$$ LANGUAGE plpgsql;
|
|
|