SQL 旋转以生成动态列

Question

我有以下数据：

我有以下代码：


select * from
(
SELECT 
d.CreatedDate,
m.siteid,
m.ProjectNum



FROM DWCorp.SSMaster m 
INNER JOIN DWCorp.SSDetail d ON d.MasterId = m.Id WHERE  ActionId = 7
)as Sourcetable
pivot
(
max(createddate)
for siteid in ([1],[2],[3],[4],[5])
) As pivottable

我希望数据看起来像这样：

最多只能有 5 个日期。我现在拥有它的方式是按我不想要的站点进行旋转。我希望它按日期旋转。

有人可以帮忙吗？我知道我可能需要使用动态 SQL，但不确定该怎么做。我已经在论坛中搜索过了，但没有找到我要找的东西。

文本输出：

CreatedDate               siteid ProjectNum
2021-04-06 13:14:01.8933333 20  OTHO00006
2021-04-28 16:40:01.9066667 20  OTHO00006
2021-05-03 22:47:01.7466667 20  OTHO00006
2021-04-28 16:42:02.3700000 20  OTHO00016
2021-05-06 13:27:01.9633333 20  OTHO00016
2021-05-27 15:10:01.7066667 20  OTHO00018
2021-06-29 13:01:01.9266667 20  OTHO00024
2021-05-12 13:38:01.8300000 20  OTHO00024
2021-06-29 13:02:04.7800000 20  OTHO00028
2021-03-25 13:00:03.6100000 21  OBEL00001
2021-08-10 19:44:01.9233333 21  OBEL00003
2021-11-03 20:45:39.2733333 21  OBEL00003
2021-04-26 18:57:34.5533333 21  OBEL00004

Answer 1

像这样的东西可以解决问题：

select projectNum, 
  [1] as Date1,
  [2] as Date2,
  [3] as Date3,
  [4] as Date4,
  [5] as Date5
from (
  select d.projectNum, d.createdDate, d.dateId
  from (
    select dd.rn as dateId, dd.createdDate, dd.projectNum
    from (
      select *, row_number() over (partition by projectNum order by createdDate asc) rn
      from your_data
      ) dd
    where rn <= 5
    -- order by 3, 1
    ) d
  ) as src
  pivot (
    max(createdDate)
    for dateId in ([1],[2],[3],[4],[5])
  ) as pvt

为了更简单并避免使用动态 sql，您可以使用 row_number 为从最旧到最新排序的每个日期分配一个 dateId，然后使用它id 来旋转数据。

Answer 2

您可以利用 row_number window 函数和 条件案例 聚合来做到这一点：

with c as (
    select Convert(date,CreatedDate) CreatedDate, ProjectNum,
      Row_Number() over (partition by ProjectNum order by createddate) col
    from t
)
select 
    ProjectNum,
    max(case when col=1 then CreatedDate end) Date1,
    max(case when col=2 then CreatedDate end) Date2,
    max(case when col=3 then CreatedDate end) Date3,
    max(case when col=4 then CreatedDate end) Date4,
    max(case when col=5 then CreatedDate end) Date5
from c
group by ProjectNum

Answer 3

试试这个，但我希望这只是一个示例用例，因为动态用例可能有 365 个 days/dates

   With dtes as (
  Select distinct trim(createdDate), row_number() over (order by 
   1) rn 
  From  DWCorp.SSMaster m 
  INNER JOIN DWCorp.SSDetail d ON d.MasterId = m.Id WHERE  
  ActionId = 7 )

    SELECT 
    m.ProjectNum, 
  
     Max(case when trim(createddate) = Select 
    trim(createdDate) from dtes where rn=1 then m.siteid end), 
    Max(case when trim(createddate) = Select 
    trim(createdDate) from dtes where rn=2 then m.siteid end)
     Max(case when trim(createddate)= Select 
    trim(createdDate) from dtes where rn=3 then m.siteid end),
    Max(case when trim(createddate)= Select 
    trim(createdDate) from dtes where rn=4 then m.siteid end),
    
       Max(case when trim(createddate)= Select 
    trim(createdDate) from dtes where rn=5 then m.siteid end)
    
  FROM DWCorp.SSMaster m 
 INNER JOIN DWCorp.SSDetail d ON d.MasterId = m.Id WHERE  
 ActionId = 7 
  group by project_num

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