Question

我有一张桌子

declare @t table (val int)

insert INto @t (val) values (420), (420), (520), (520), (520), (620)

select 
    val, ROW_NUMBER() OVER (PARTITION BY val order by val) RN 
from @t

返回输出：

val RN
------
420 1
420 2
520 1
520 2
520 3
620 1

期望的输出：

val RN
420 1
420 2
NULL NULL
520 1
520 2
520 3
NULL NULL
620 1

如何实现这一目标？

Answer 1

这种操作应该在应用程序中完成。您可以在SQL Server中执行此操作，但它实际上更多是一个有趣的技巧，然后是推荐的答案。

我们的想法是加入您想要的行，然后使用t.n IN (2)按顺序获取结果：

order by

我要强调，这是对select val, rn from ((select val, ROW_NUMBER() OVER (PARTITION BY val order by val) as rn, 1 as ordering, val as val2 from @t t ) union all (select NULL, NULL, 2, val from @t t group by val ) ) t order by val2, ordering, rn;陈述的力量的证明。真正的答案是在应用层执行此操作。

Answer 2

这有效：

declare @t table (val int)
declare @n table( val int)

insert INTO @n(val) values( NULL )
insert INto @t (val)values (420),(420),(520),(520),(520),(620)

SELECT T2.val, T2.RN AS RN
FROM (
select T.val AS GRP, T.val,ROW_NUMBER()OVER(PARTITION BY T.val order by T.val)RN from @t AS T
union
select DISTINCT T.VAL AS GRP, NULL AS val, NULL AS RN FROM @t AS T
) AS T2
ORDER BY T2.GRP, ISNULL(T2.RN, 99)

要使摘要行更改主SELECT：

SELECT T2.val, T2.RN AS RN
FROM (
select T.val AS GRP, T.val,ROW_NUMBER()OVER(PARTITION BY T.val order by     T.val) RN from @t AS T
union 
select T.VAL AS GRP, SUM(T.VAL) AS val, NULL AS RN FROM @t AS T GROUP BY T.Val
) AS T2
ORDER BY T2.GRP, ISNULL(T2.RN, 99)

Answer 3

我们都讨厌游标，但对于这个愚蠢而且希望使用小数据集的东西，你可以在sql而不是app层中强制它。但感觉很愚蠢。但你可以。

对于它的价值，这个解决方案避免了额外的＆＃34;最后的NULL行。因此，它在技术上完全匹配您想要的输出。其他人到目前为止还没有。

type='number'

如何在每个序列后实现Null行

3 个答案: