Funso (Chichewa): Kodi misika ingati inalemba mitengo ya chimanga ndi nyemba pa tsiku limodzi lomwelo?
Question (English): How many markets recorded prices for maize and beans on the same date?
Table: commodity_prices (difficulty: hard)
SQL: SELECT COUNT(DISTINCT m1.market) FROM commodity_prices m1 JOIN commodity_prices m2 ON m1.market = m2.market AND m1.collection_date = m2.collection_date WHERE m1.commodity = 'Maize' AND m2.commodity = 'Beans';
Result: [(54,)]