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
http://www.nowcoder.com/practice/17f22851cf204019b51a36761a3afc79
SELECT v.vend_id, COUNT(p.vend_id) as prod_id
FROM Vendors v left join Products p
on v.vend_id = p.vend_id
group by v.vend_id
order by v.vend_id asc;