表的SQL Select语句2008

Question

我有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 

我怎么会以这样的方式选择这个表，我得到

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

有一种使用枢轴的方式，或者这将是最好的方法？

Answer 1

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

Answer 2

我知道我有点迟到了，但是这不就是更接近你在找什么：

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，this link讨论代列的动态。

祝你好运！

马特