select 
  COUNT(*) as count,
  date_trunc('day', orders.createdAt) as day
from orders
WHERE orders.createdAt BETWEEN date_trunc('week', current_date) AND date_trunc('week', current_date) + INTERVAL '6 days'
GROUP BY orders.createdAt

Bu şekilde sonuç geliyor, veri yoksa 0 yazdırırsınız.