标签：sql style class col mysq mysql sele select tin
方法一：
distinct
select count(distinct CName) from Course
方法二：
使用分组 group by
select count(1) from Course group by CName
标签：sql style class col mysq mysql sele select tin
原文地址：https://www.cnblogs.com/LYliangying/p/9563966.html
