Question

我想通过传递日期直到到达最终日期来创建递归cte。谁能给我示范如何做的例子

我需要输入开始日期和结束日期，并计算出每年有多少学生！

其中：date和：finaldate是输入

 with seventeen as 
(
    select  count(studentid)
    from students s
    join periodrange p on p.idx = s.periodrangeidx
    where p.validdate between :date and :finaldate
)

我想要每年的学生总数

像这样的事情还能奏效吗，或者我梦想到遥远的CTE

Answer 1

您不需要CTE，只需使用分组依据并计数：

select  count(studentid), extrac(year from p.validatdate) as Year
from students s
join periodrange p on p.idx = s.periodrangeidx
where p.validdate between :date and :finaldate
Group by extrac(year from p.validatdate), studentid

递归CTE如何使用它

1 个答案: