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 v.vend_id vend_id,count(p.prod_id) prod_id from Vendors v left join Products p on v.vend_id = p.vend_id group by vend_id order by vend_id;