19. Payment method mix by day
Asked in screens shaped like: Stripe, PayPal, Adyen
Turn payment methods from rows into columns so each day is a single row with card, ach, and wallet totals. Warehouses have a PIVOT clause; plain SQL does it with conditional aggregation.
Requirements
- Columns: paid_day, card, ach, wallet
- paid_day is the date part of paid_at
- Each method column sums that method’s amount for the day, 0 when absent
- All money columns rounded to 2 decimals, ordered by paid_day
Expected output
paid_day, card, ach, wallet
Row order is graded, so ORDER BY matters here.
Tables this problem reads. The full warehouse is available in thesandbox.
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 ()
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