25. Hours from order to settlement
Asked in screens shaped like: Stripe, Adyen, PayPal
Treasury wants average hours between ordered_at and paid_at, by payment method. One payment row per paid order in this warehouse. Return method and avg_hours rounded to 2 decimals, slowest method first.
Requirements
- Columns: method, avg_hours
- avg_hours is ROUND(AVG(hours from ordered_at to paid_at), 2)
- Join payments to orders on order_id
- Order by avg_hours descending, then method
Expected output
method, avg_hours
Row order is graded, so ORDER BY matters here.
Tables this problem reads. The full warehouse is available in thesandbox.
orders
~200 rows
Order headers. One row per order, so amount is the order total — not a line total.
- order_idINTEGER— 1000–1199
- customer_idTEXT— C01–C12
- countryTEXT— US, DE, IN, UK, BR
- amountREAL
- statusTEXT— 'completed' or 'cancelled'
- ordered_atTEXT— YYYY-MM-DD HH:MM:SS
payments
~182 rows
Settlements. Cancelled orders have no payment row, which is the anti-join case.
- payment_idINTEGER
- order_idINTEGER— joins orders
- methodTEXT— card, ach, wallet
- amountREAL
- paid_atTEXT
Pick a warehouse dialect above the editor. The engine is still SQLite; common syntax is rewritten before it runs.
SQLite cheat sheet
- Truncate to day
DATE(ordered_at) - Current date
DATE('now') - Conditional
CASE WHEN … THEN … ELSE … END - String aggregate
GROUP_CONCAT(col, ", ") - JSON field
json_extract(payload, '$.source') - Date difference
JULIANDAY(a) - JULIANDAY(b) - Filter a window
CTE, then WHERE rn = 1 - Median
ROW_NUMBER + COUNT(*) OVER ()
Revealed one at a time. The reference query stays in the Solution tab.
Loading the reference solution for Pro.Why it works
Run your query to see the result set.
Submit to run the checks.
Why it works
Pro problem
Hard problems unlock with Pro
Easy pads stay free. Medium and hard SQL and Python problems — editor, tests, hints, and solutions — open after you upgrade to Pro or coaching.
See plansPractice free easy problems