Question

我有以下结果集：

ID          P1Score P2Score P3Score
===================================
22117617    NULL    50      NULL
22117617    1       NULL    NULL    
22117617    NULL    NULL    40

我想要做的是，将这些行合并为一个。

我想将P1Score的值放在P1score列中，与P2score和P3score相同。

如何实现这一目标？

Answer 1

select ID,
max(ISNULL(P1Score,0)),
max(ISNULL(P2Score,0)),
max(ISNULL(P3Score,0))
from [Score] group by ID

Answer 2

你可以直接使用group by和sum（）函数，因为如果你有单个Id的多个分数，那么sum就是合适的。

SELECT ID
    ,sum(P1Score) AS P1Score
    ,sum(P2Score) AS P2Score
    ,sum(P3Score) AS P3Score
FROM [Score]
GROUP BY ID

Answer 3

如果您使用的是SQL Server 2012或更高版本，则可以使用MAX with OVER：

SELECT DISTINCT ID,
                MAX(P1Score) OVER (ORDER BY ID) P1Score,
                MAX(P2Score) OVER (ORDER BY ID) P2Score,
                MAX(P3Score) OVER (ORDER BY ID) P3Score
FROM YourTable

输出：

ID          P1Score P2Score P3Score
22117617    1       50      40

甚至转动：

SELECT *
FROM YourTable
UNPIVOT (
    [Values] FOR PScores IN (P1Score, P2Score, P3Score)
) unp
PIVOT (
    MAX([Values]) FOR PScores IN (P1Score, P2Score, P3Score)
) piv

在sql中将多行合并为一行

3 个答案: