sql-server-2008 - 表 SQL 2008 的选择语句

Question

我有一个包含 3 列的表，代表一个矩阵：

i j val
-------
1 1  1
1 2  12
1 3  4
2 1  3
2 2  4
2 3  4
3 1  0
3 2  2
3 3  2

我将如何以我得到的方式选择此表

a1 a2 a3
-------
1 12  4
3  4  4
0  2  2

有没有办法使用 pivot 或者这里最好的方法是什么？

Answer 1

我知道我参加聚会有点晚了，但这不是更接近您正在寻找的东西：

SELECT [1] as a1, [2] as a2, [3] as a3
FROM
(
SELECT i, j, val
FROM T) AS source
PIVOT
(
    MAX(val)
    FOR j IN ([1], [2], [3])
) as pvt

此外，此链接还讨论了动态生成列。

祝你好运！

马特

Answer 2

SELECT [1] AS a1,
       [2] AS a2,
       [3] AS a3
FROM T
PIVOT (MAX(val) FOR j IN ([1],[2],[3])) AS P