题解 | #列出供应商及其可供产品的数量#
列出供应商及其可供产品的数量
https://www.nowcoder.com/practice/17f22851cf204019b51a36761a3afc79
SELECT vd.vend_id, COALESCE(COUNT(prod_id),0) AS prod_id FROM Vendors AS vd LEFT JOIN Products AS p ON vd.vend_id = p.vend_id GROUP BY vend_id ORDER BY vend_id