SQL pattern · P04 · 16 problems
Learn it first · P04The Aggregation and GROUP BY
Graded problems on aggregation and GROUP BY, from easy to hard.
16 problems · about 1 h 40 min in all
GROUP BY that answers a different questionOne extra grouping column splits a per-customer total into per-status rows.Read the lesson →Easy
01Paid and Refunded Orders per Customer4 min →02Customers in Each Country3 min →03Top 2 Customers by Paid Spend5 min →04Customers with at Least 2 Orders4 min →05Revenue by Category5 min →06Daily Active Users5 min →07First and Last Login per User4 min →08Survey Sends, Responses, and Average Rating5 min →09Average Tip per Delivery5 min →10Orders and Unique Customers per Day6 min →