Question

是否想找到一个数字的阶乘之和？

但是我需要像5这样的结果之和！是120 在这个我想要1 + 2 + 0 = 3

Answer 1

这可以通过递归CTE来实现：

--here you decide what factorial to calculate
declare @i int = 5;
;with cte as(
    select 1 n, 1 factorial
    union all
    select n + 1, factorial * (n + 1) from cte
    where n < @i
)
select factorial,
       --just to make sure we correctly sum all digits
       (factorial%100000)/10000 + 
       (factorial%10000)/1000 + 
       (factorial%1000)/100 + 
       (factorial%100)/10 + 
       factorial%10 DigitsSum
from cte
where n = @i

Answer 2

您可以使用如下代码：

declare @a int
set @a = 120
declare @temp varchar(20)
set @temp = cast(@a as varchar(20))
declare @Result int
set @Result = 0
declare @tempLength int
set @tempLength = DATALENGTH(@temp)
while @tempLength > 0
begin
    set @Result = @Result + cast(SUBSTRING(@temp, @tempLength, 1) as int)
    set @tempLength = @tempLength - 1
end
select @Result

变量“ a”与您的阶乘结果相同。

Answer 3

尝试使用substring（）函数并分离数字，然后将所有数字加在一起。

Answer 4

您可以从sum of factorial of the no创建函数以找出数字的阶乘。然后使用以下查询找到总和：

    DECLARE @var1 int   
    select @var1 = dbo.Factorial(5)

    ;WITH i AS (
        SELECT @var1 / 10 n, @var1 % 10 d

        UNION ALL

        SELECT n / 10, n % 10
        FROM i
        WHERE n > 0
    )
    SELECT SUM(d)
    FROM i;

否的阶乘之和

4 个答案: