Write SQL to detect recurring non-subscription users

For this problem, use two tables: merchant and transaction. The merchant table contains merchant_id, merchant_name, country, created_at, and vertical. The transaction table contains txn_id, merchant_id, customer_id, amount_cents, currency, product_type, created_at, status, and card_fingerprint. Assume the current date is 2025-06-01. The 180-day analysis window starts on 2024-12-04 and ends on 2025-06-01, inclusive. The last 30 days start on 2025-05-03 and end on 2025-06-01,…