Get created as well as deleted entries of last week

Question

With this query I can get all entries created during the last week:

SELECT day, COALESCE(ct, 0) AS ct
FROM  (SELECT now::date - d AS day FROM generate_series (0,         


        

Answer 1

Since both timestamps can exist 0 - n times in the time frame and independent from each other, you have to do more:

Requires Postgres 9.3+:

WITH var(ts_min) AS (SELECT date_trunc('day', now()) - interval '6 days')
SELECT day
     , COALESCE(c.created, 0) AS created
     , COALESCE(d.deleted, 0) AS deleted
FROM   var v
CROSS  JOIN LATERAL (
   SELECT d::date AS day
   FROM   generate_series (v.ts_min
                         , v.ts_min + interval '6 days'
                         , interval '1 day') d
   ) t
LEFT   JOIN (
   SELECT created_at::date AS day, count(*) AS created
   FROM   entries
   WHERE  created_at >= (SELECT ts_min FROM var)
   GROUP  BY 1
   ) c USING (day)
LEFT   JOIN (
   SELECT canceled_at::date AS day, count(*) AS deleted
   FROM   entries
   WHERE  canceled_at >= (SELECT ts_min FROM var)
   GROUP  BY 1
   ) d USING (day)
ORDER  BY 1;

The CTE var is only for the convenience to provide the starting timestamp once.

SQL Fiddle.

Answer 2

At first glance it looks like your performing a count function rather than a sum which is what you need, your simply just counting each record twice.

sum( CASE WHEN (created_at >= date_trunc('day', now()) - interval '6d') 
       THEN 1 ELSE 0 END) AS ct,
sum(CASE WHEN (canceled_at >= date_trunc('day', now()) - interval '6d') 
       THEN 1 ELSE 0 END) AS dl  

You need to use sum which will then add all the cases where you case when is returning 1 rather than count which just counts all the values regardless whether they are 1 or 0!