Sentry db query - issues

query.sql

SET TIME ZONE 5;

SELECT
  error_count,
  date_added,
  error_count - lag(error_count, 1)
  OVER () delta,
  avg(error_count)
  OVER () average_count,
  CASE WHEN error_count > avg(error_count) OVER ()
    THEN 'BAD'
  ELSE '' END
FROM (
       SELECT
         count(id)                         error_count,
         date_trunc('hour', date_added) AS date_added
       FROM sentry_eventmapping
       WHERE project_id = 28 AND date_added >= NOW() + INTERVAL '-24 hour'
       GROUP BY date_trunc('hour', date_added)
       ORDER BY date_trunc('hour', date_added)
     ) AS event