问答题 select month(入学日期) as 入学月份,count(*) as 人数 from students group by month(入学日期)
问答题 declare @a char(8) set @a="计算机" select计算机专业人数=count(*) from students where left(专业,3)=@a
问答题 declare @a numeric(5,2),@b numeric(5,2) set @a=(select max(成绩) from score) set @b=(select min(成绩) from score) print @a-@b