Materialized view

create_tables.sql

@@ -34,3 +34,7 @@ CREATE TABLE core_data (
      batch_id INT REFERENCES batch(batch_id)
      -- should have a primary key on what? (geography_id, batch_id) ?
 );
+
+CREATE MATERIALIZED VIEW daily_core_data AS
+SELECT core_data.* FROM (SELECT state_name, MAX(batch_id) as max_bid FROM core_data GROUP BY state_name,data_date)
+AS x JOIN core_data ON batch_id=x.max_bid AND core_data.state_name=x.state_name;

external_query.sql

@@ -32,16 +32,22 @@ SELECT state_name, MAX(core_data.batch_id) as max_bid
     WHERE batch.is_published = TRUE
     GROUP BY state_name;
 
-/* States current: What's the latest published (non-preview) data for all states? */
+/* States current: What's the latest published (non-preview) data for all states?
+As written, this assumes that the latest date published for any state is the most recent for all states.
+*/
+WITH temp (latest_date) AS (SELECT MAX(data_date) FROM core_data)
 SELECT * FROM (
 	SELECT state_name, MAX(core_data.batch_id) as max_bid
-		FROM core_data INNER JOIN batch ON core_data.batch_id = batch.batch_id
-		WHERE batch.is_published = TRUE
+		FROM temp,core_data INNER JOIN batch ON core_data.batch_id = batch.batch_id
+		WHERE batch.is_published = TRUE AND core_data.data_date = temp.latest_date
 		GROUP BY state_name) AS latest_state_batches
 	INNER JOIN core_data ON (
 		core_data.batch_id = latest_state_batches.max_bid AND
 		core_data.state_name = latest_state_batches.state_name)
 	INNER JOIN batch ON (core_data.batch_id = batch.batch_id);
+
+/* States current/on a date using materialized view */
+SELECT * FROM daily_core_data WHERE data_date = '2020-03-20';
 
 /* States daily: What's the published daily data for all states, incorporating all edits? */
 SELECT * FROM (

init_test_data.sql

@@ -133,4 +133,17 @@ BEGIN
 		('NY', '2020-03-21 17:00:00', '2020-03-21 17:56:00', '2020-03-21', 210, 'JK', 'NY afternoon', last_batch_id);
 END $$;
 
+/* Revise data from the 20th. This will cause issues with naive queries that just get the most recent batchid */
+DO $$
+DECLARE last_batch_id BIGINT;
+BEGIN
+	INSERT INTO batch
+		(created_at, shift_lead, batch_note, is_published, is_revision, data_entry_type) VALUES
+		('2020-03-21 20:05:00', 'AS', '3/20 night', TRUE, TRUE, 'push')
+		RETURNING batch_id INTO last_batch_id;
+	INSERT INTO core_data 
+		(state_name, last_update_time, last_check_time, data_date, tests, checker, public_notes, batch_id) VALUES
+		('PA', '2020-03-21 17:00:00', '2020-03-21 17:55:00', '2020-03-20', 167, 'AS', 'PA afternoon', last_batch_id);
+END $$;
+
 SELECT * FROM core_data INNER JOIN batch ON core_data.batch_id = batch.batch_id;