Question

这是一个奇怪的问题，我知道在SQL中不这样做会更容易，但它会让我的生活变得更轻松。

基本上我有一个列结果集，我需要将其转换为3列，而不是基于任何标准。

例如

成：

1  2  3
4  5  6
7

在这种情况下，它总是一个固定的3列结果。

目前我正在使用游标并插入表变量，这似乎有点可怕。必须有更好的方法。

由于

Answer 1

试试这个：

declare @t table(n int)

insert @t(n) values(1),(2),(3),(4),(5),(6),(7),(8),(9),(10)

select [0],[1],[2]
from
(
    select n
    , (ROW_NUMBER() over (order by n) - 1) % 3 c
    , (ROW_NUMBER() over (order by n) - 1) / 3 r
    from @t
) x
pivot (max(n) for c in ([0], [1], [2])) p

Answer 2

根据PIVOT operator尝试此解决方案：

DECLARE @MyTable TABLE (
    ID INT PRIMARY KEY
);
INSERT @MyTable VALUES (11)
INSERT @MyTable VALUES (22)
INSERT @MyTable VALUES (33)
INSERT @MyTable VALUES (44)
INSERT @MyTable VALUES (55)
INSERT @MyTable VALUES (66)
INSERT @MyTable VALUES (77);

WITH RowsWithNum
AS (
    SELECT  *, ROW_NUMBER() OVER(ORDER BY ID) - 1 AS RowNum -- ORDER BY ID -> defines the order for numbering rows. ID values should be uniques. Thus results will be deterministic.
    FROM    @MyTable
), Groups 
AS (
    SELECT  ID, RowNum % 3 AS ColumnID, RowNum / 3 AS GroupID
    FROM    RowsWithNum
)
SELECT  *
FROM    Groups AS x
PIVOT( MAX(x.ID) FOR x.ColumnID IN ([0], [1], [2]) ) AS pvt -- Comment this line to see what results return [Groups] common table expression

结果：

GroupID 0   1    2
------- --- ---- ----
0       11  22   33
1       44  55   66
2       77  NULL NULL

Answer 3

这是可能的，但男人这是一个丑陋的要求。这个真的属于表示层，而不是sql。

WITH original As
(
    SELEZCT MyColumn, row_number() over (order by MyColumn) as ordinal
    FROM RestOfOriginalQueryHere
), 
Grouped As 
(
    SELECT MyColumn, ordinal / 3 As row, ordinal % 3 As col
    FROM original
)
SELECT o1.MyColumn, o2.MyColumn, o3.MyColumn
FROM grouped g1
LEFT JOIN grouped g2 on g2.row = g1.row and g2.col = 1
LEFT JOIN grouped g3 on g2.row = g1.row and g3.col = 2 
WHERE g1.col = 0

t-sql单列结果设置为3列

3 个答案: