medium10 pts · first answer countssqlwindow-functions

Latest order per customer

Which approach returns exactly one row per customer: their most recent order?

A.GROUP BY customer_id and select MAX(created_at) with all other order columnsB.Use ROW_NUMBER() OVER (PARTITION BY customer_id ORDER BY created_at DESC) and keep rows where it equals 1C.Use RANK() OVER (ORDER BY created_at) and keep rank 1D.Use SELECT DISTINCT customer_id, created_at

← Revenue doubled after a join Running total of sales →