Goal Charts in SQL

.sql

WITH dates as (
  SELECT ds, row_number() OVER () as rnum 
  FROM generate_series(
      date_trunc('month', now())::timestamp AT TIME ZONE 'PST',
      date_trunc('month', now() + INTERVAL '1 month')::timestamp AT TIME ZONE 'PST',
      '24 hours') 
    as ds
)

SELECT ds, goal, 
  CASE WHEN LAG(metric) OVER (ORDER BY ds) = metric 
    THEN NULL 
    ELSE metric 
  END as metric
FROM (
  SELECT a.ds, 
    START_METRIC + ((a.rnum-1) * (END_GOAL-START_METRIC) / (DAYS_IN_MONTH-1)) as goal, 
    COUNT(DISTINCT b.id) as metric
  FROM dates a
  LEFT OUTER JOIN TABLE_NAME b
  ON date_trunc('day', a.ds) >= date_trunc('day', b.created_at AT TIME ZONE 'PST')
  AND date_part('month', b.created_at AT TIME ZONE 'PST') = MONTH_OF_YEAR
  GROUP BY 1,2
) a