MySql count去掉重复语句
1.
select count(distinct CName) from Course
2.
select count(CName) from (select distinct CName from Course) as temp
摘自 王贺的博客
MySql count去掉重复语句
MySql count去掉重复语句
2.
MySql count去掉重复语句
2.
MySql count去掉重复语句
2.