Cheatsheet with sql

snippet.sql

SELECT
  EXTRACT(MONTH FROM payment_date)        AS month,
  COUNT(*)                                AS total_count,
  SUM(amount)                             AS total_amount,
  COUNT(*)    FILTER (WHERE staff_id = 1) AS mike_count,
  SUM(amount) FILTER (WHERE staff_id = 1) AS mike_amount,
  COUNT(*)    FILTER (WHERE staff_id = 2) AS jon_count,
  SUM(amount) FILTER (WHERE staff_id = 2) AS jon_amount
FROM payment
GROUP BY month
ORDER BY month;