query and presentation code

retention_playbook/describing_retention/postgres.sql

@@ -0,0 +1,54 @@
+-- For details on how to use this report, visit
+-- https://modeanalytics.zendesk.com/hc/en-us/articles/203484670
+
+WITH 
+
+users AS (
+  SELECT customer_id AS user_id,
+         signup_date AS activated_at
+    FROM benn.sample_customer_table
+),
+
+events AS (
+  SELECT customer_id AS user_id,
+         event_name,
+         event_date AS occurred_at
+    FROM benn.sample_event_table
+)
+
+
+SELECT DATE_TRUNC('day',z.activated_at) AS signup_date,
+       z.counter AS user_period,
+       COUNT(z.user_id) AS signups,
+       COUNT(CASE WHEN events > 0 THEN z.user_id ELSE NULL END) AS retained_users
+  FROM (
+
+SELECT u.user_id,
+       u.counter,
+       u.activated_at,
+       u.period_start,
+       COUNT(e.user_id) AS events
+  FROM (
+        SELECT user_id,
+               activated_at,
+               activated_at + (counter * INTERVAL '1 day') AS period_start,
+               activated_at + ((counter + 1) * INTERVAL '1 day') AS period_end,
+               counter
+          FROM users u
+          JOIN (SELECT s.a AS counter FROM generate_series(1,9) AS s(a)) c
+            ON c.counter < 10
+           AND c.counter > 0
+         WHERE u.activated_at >= '2014-10-31'::TIMESTAMP - INTERVAL '11 day'
+       ) u
+  LEFT JOIN events e
+    ON e.user_id = u.user_id
+   AND e.occurred_at >= u.period_start
+   AND e.occurred_at < u.period_end
+   AND e.event_name = 'engagement_event'
+   AND e.occurred_at >= '2014-10-31'::TIMESTAMP - INTERVAL '11 day'
+ WHERE u.period_start <= '2014-10-31'::TIMESTAMP
+ GROUP BY 1,2,3,4
+       ) z
+ GROUP BY 1,2
+ ORDER BY 1,2
+LIMIT 100