题解 | #返回产品名称和每一项产品的总订单数#
返回产品名称和每一项产品的总订单数
http://www.nowcoder.com/practice/1c64fd9048364a58a8ffa541720359a4
SELECT prod_name,IF(orders IS NULL,0,orders) AS orders
FROM Products AS p
LEFT JOIN (SELECT prod_id,COUNT(*) AS orders FROM OrderItems GROUP BY prod_id) AS oi
ON p.prod_id = oi.prod_id
ORDER BY prod_name;
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