#57 Add sql to create lookup table

congestion_network_creation/sql/creation/segment_centreline_lookup.sql

@@ -0,0 +1,27 @@
+-- Lookup table
+
+CREATE TABLE congestion.segment_centreline_lookup AS
+
+with temp as (
+	select row_number() over() as uid, a.*, main_street, start_int_name, end_int_name 
+	from congestion.segment_centreline a
+	left join congestion.segment_centreline_name using (segment_set) )
+, unnest_seg AS (
+	select uid, unnest(segment_set) as segment_id , start_vid, end_vid, start_int, end_int, geo_id_set, length as cent_length 
+	from temp)
+
+, seg_info AS (
+	select uid, sum(total_length) as segment_set_length, unnest_seg.start_vid, unnest_seg.end_vid, start_int, end_int, geo_id_set, cent_length 
+	from unnest_seg
+	inner join congestion.network_segments using (segment_id)
+	group by uid, unnest_seg.start_vid, unnest_seg.end_vid, start_int, end_int, geo_id_set, cent_length)
+
+select uid, segment_id, start_vid, end_vid, 
+		seg_info.start_int, seg_info.end_int, 
+		seg_info.geo_id_set, segment_set_length, seg_info.cent_length
+from unnest_seg
+inner join seg_info using (uid,start_vid, end_vid) 
+
+
+COMMENT ON MATERIALIZED VIEW congestion.segment_centreline_lookup
+    IS 'A Lookup Table between segment_ids in the congestion network and the geo_id in centreline ';