sql - 将多行转换为多列

Question

这是使用 SQL 服务器

ID       ID1      Days     Rank
96972    1        2976     1
96972    174      2976     2
96972    173      2966     3
96972    175      2966     4
96972    176      2963     5
96972    177      2961     6
96972    178      2960     7
96972    179      2952     8
96972    180      2945     9
96972    181      135      10

我在结果集中做了 Rank 列，如下所示

row_number() OVER(Partition by id ORDER BY somedate)  AS TimeLineOrders

我想在单行中显示这些结果

Timeline1     Timeline2     TimeLine3     Timeline4    Timeline 10
96972         ID1+Days      ID1+Days      ID1+Days     ID1+Days     ID1+Days

任何人都可以帮助我吗？

Answer 1

由于缺乏表结构和最终结果，很难确切地知道您在寻找什么。看来您需要PIVOT数据。您可以PIVOT使用静态版本或动态版本。

使用数据样本创建表：

create table tableA
(
    id int,
    id1 int,
    days int
);

insert into tableA values
(96972,   1,   2976),
(96972,   174, 2976),
(96972,   173, 2966),
(96972,   175, 2966),
(96972,   176, 2963),
(96972,   177, 2961),
(96972,   178, 2960),
(96972,   179, 2952),
(96972,   180, 2945),
(96972,   181, 135);

静态版本，具有硬编码到枢轴的值：

select *
from 
(
    select id, 
        'Timeline_' + cast(ROW_NUMBER() over(PARTITION by id order by days desc) as varchar(10)) col,
        id1 + days value
    from tableA
) x
pivot
(
    max(value)
    for col in ([Timeline_1], [Timeline_2], [Timeline_3], [Timeline_4], 
                [Timeline_5], [Timeline_6], [Timeline_7], [Timeline_8], 
                [Timeline_9], [Timeline_10])
) p

动态版本，列在运行时生成：

DECLARE @cols AS NVARCHAR(MAX),
    @query  AS NVARCHAR(MAX)

select @cols = STUFF((SELECT ',' + QUOTENAME( 'Timeline_' + cast(x.rn as varchar(10))) 
                    from tableA
                    cross apply 
                    (
                        select ROW_NUMBER() over(PARTITION by id order by days desc) rn
                        from tableA
                    ) x
                    group by x.rn
                    order by x.rn
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')

set @query = 'SELECT id, ' + @cols + ' from 
             (
                select id, 
                    ''Timeline_'' + cast(ROW_NUMBER() over(PARTITION by id order by days desc) as varchar(10)) col,
                    id1 + days value
                from tableA
            ) x
            pivot 
            (
                max(value)
                for col in (' + @cols + ')
            ) p '

execute(@query)