add suggested_name output to OBS_GetMeta. fixes #279

doc/measures_functions.md

@@ -246,6 +246,7 @@ fail.
 
 Metadata Output Key | Description
 --- | -----------
+suggested_name | A suggested column name for adding this to an existing table
 numer_id | Identifier for desired measurement
 numer_timespan | Timespan that will be used of the desired measurement
 numer_name | Human-readable name of desired measure

src/pg/sql/41_observatory_augmentation.sql

@@ -180,6 +180,14 @@ BEGIN
     ), meta AS (SELECT
         id,
         f.numer_id,
+        LOWER(TRIM(BOTH '_' FROM regexp_replace(CASE WHEN f.numer_id IS NOT NULL
+          THEN CASE
+            WHEN normalization ILIKE 'area%%' THEN numer_colname || ' per sq km'
+            WHEN normalization ILIKE 'denom%%' THEN numer_colname || ' rate'
+            ELSE numer_colname
+          END || ' ' || m.numer_timespan
+          ELSE geom_name || ' ' || m.geom_timespan
+        END, '[^a-zA-Z0-9]+', '_', 'g'))) suggested_name,
         CASE WHEN f.numer_id IS NULL THEN NULL ELSE numer_aggregate END numer_aggregate,
         CASE WHEN f.numer_id IS NULL THEN NULL ELSE numer_colname END numer_colname,
         CASE WHEN f.numer_id IS NULL THEN NULL ELSE numer_geomref_colname END numer_geomref_colname,
@@ -237,6 +245,7 @@ BEGIN
           'timespan_rank', dense_rank() OVER (PARTITION BY id ORDER BY numer_timespan DESC),
           'score_rank', dense_rank() OVER (PARTITION BY id ORDER BY score DESC),
           'score', scores.score,
+          'suggested_name', cdb_observatory.FIRST(meta.suggested_name),
           'numer_aggregate', cdb_observatory.FIRST(meta.numer_aggregate),
           'numer_colname', cdb_observatory.FIRST(meta.numer_colname),
           'numer_geomref_colname', cdb_observatory.FIRST(meta.numer_geomref_colname),

src/pg/test/expected/41_observatory_augmentation_test.out

@@ -150,6 +150,15 @@ t|t|t|t|t|t|t|t|t|t|t|t|t|t|t
 obs_getmeta_conflicting_metadata
 t
 (1 row)
+obs_getmeta_suggested_name
+t
+(1 row)
+obs_getmeta_suggested_name_area
+t
+(1 row)
+obs_getmeta_suggested_name_denom
+t
+(1 row)
 obs_getdata_geomval_empty_null
 t
 (1 row)

src/pg/test/sql/41_observatory_augmentation_test.sql

@@ -398,6 +398,21 @@ SELECT cdb_observatory.OBS_GetMeta(cdb_observatory._TestPoint(),
   '[{"numer_id": "us.census.acs.B01001002", "denom_id": "us.census.acs.B01001002", "geom_id": "us.census.tiger.census_tract"}]') IS NULL
 AS obs_getmeta_conflicting_metadata;
 
+-- OBS_GetMeta provides suggested name for simple meta request
+SELECT cdb_observatory.OBS_GetMeta(cdb_observatory._TestPoint(),
+  '[{"numer_id": "us.census.acs.B01003001"}]'
+)->0->>'suggested_name' = 'total_pop_2011_2015' obs_getmeta_suggested_name;
+
+-- OBS_GetMeta provides suggested name for simple meta request with area norm
+SELECT cdb_observatory.OBS_GetMeta(cdb_observatory._TestPoint(),
+  '[{"numer_id": "us.census.acs.B01003001", "normalization": "area"}]'
+)->0->>'suggested_name' = 'total_pop_per_sq_km_2011_2015' obs_getmeta_suggested_name_area;
+
+-- OBS_GetMeta provides suggested name for simple meta request with denom
+SELECT cdb_observatory.OBS_GetMeta(cdb_observatory._TestPoint(),
+  '[{"numer_id": "us.census.acs.B01001002", "normalization": "denom"}]'
+)->0->>'suggested_name' = 'male_pop_rate_2011_2015' obs_getmeta_suggested_name_denom;
+
 -- OBS_GetData/OBS_GetMeta by id with empty list/null
 WITH data AS (SELECT * FROM cdb_observatory.OBS_GetData(ARRAY[]::TEXT[], null))
 SELECT ARRAY_AGG(data) IS NULL AS obs_getdata_geomval_empty_null FROM data;