Oracle - 将行转置为列答案

【问题标题】：Oracle - Transpose Row into ColumnOracle - 将行转置为列
【发布时间】：2018-10-20 05:46:00
【问题描述】：

我想将以下行结果转换为列。我正在考虑 PIVOT，但我不相信我能达到预期的结果。

原样：

ID_NCM | DESTINATION | START      | END  
36393  | PE          | 01-01-2018 | 10-31-2018
36393  | PE          | 11-01-2018 | 12-31-9999

成为：

ID_NCM | DESTINATION | CURRENT_START | CURRENT_END | FUTURE_START | FUTURE_END
36393  | PE          | 01-01-2018    | 10-31-2018  | 11-01-2018   | 12-31-9999

我是否在这里遗漏了一些表结构概念，从而无法使用 select 语句实现所需的布局？

谢谢。

【问题讨论】：

标签： sql oracle oracle12c transpose

【解决方案1】：

你可以试试这样的 -

select id_ncm,
       destination,
       max(decode(myrank, 1, start_date)) current_start,
       max(decode(myrank, 1, end_date)) current_end,
       max(decode(myrank, 2, start_date)) future_start,
       max(decode(myrank, 2, end_date)) future_end
  from (select id_ncm,
               destination,
               start_date,
               end_date,
               rank() over(partition by id_ncm order by start_date, end_date) myrank
          from your_table) v1
 group by id_ncm, destination

【讨论】：

我会试一试...谢谢

【解决方案2】：

您可以直接将grouping by ID_NCM,DESTINATION 与min 和max 函数作为：

with t(ID_NCM,DESTINATION,"START","END") as
(  
 select 36393,'PE',date'2018-01-01',date'2018-10-31' from dual union all
 select 36393,'PE',date'2018-01-11',date'9999-12-31' from dual 
)
select ID_NCM,DESTINATION,
       min("START") as CURRENT_START,min("END") as CURRENT_END,
       max("START") as FUTURE_START,max("END") as FUTURE_END
  from t
 group by ID_NCM,DESTINATION

ID_NCM  DESTINATION CURRENT_START  CURRENT_END   FUTURE_START  FUTURE_END
------  ----------- -------------  ------------  ------------  -----------
36393       PE       01.01.2018     31.10.2018    11.01.2018   31.12.9999

附注START 和 END 是 Oracle 中的保留关键字，所以用双引号括起来。

编辑：由于您的最后评论，您可以通过添加相关子查询来进行更改，如下所示：

with t(ID_NCM,DESTINATION,"START","END",tax_rate) as
(  
 select 36393,'PE',date'2018-01-01',date'2018-10-31',0.06 from dual union all
 select 36393,'PE',date'2018-01-11',date'9999-12-31',0.04 from dual 
)
select ID_NCM,DESTINATION,
       min("START") as CURRENT_START,min("END") as CURRENT_END,
       max("START") as FUTURE_START,max("END") as FUTURE_END,
       (select tax_rate from t where "START"=date'2018-01-01' and "END"=date'2018-10-31') 
                                                                         as current_rate,
       (select tax_rate from t where "START"=date'2018-01-11' and "END"=date'9999-12-31') 
                                                                         as future_rate
  from t
 group by ID_NCM,DESTINATION

ID_NCM  DEST   CURRENT_START  CURRENT_END  FUTURE_START  FUTURE_END CURRENT_RATE FUTURE_RATE
------  ----- -------------  ------------  ------------  ----------- ----------- -----------
36393   PE     01.01.2018     31.10.2018    11.01.2018   31.12.9999     0,06          0,04

Edited Rextester Demo

【讨论】：

虽然我采用了第一个示例作为解决方案，但我意识到您的示例要简单得多，而且在我的情况下，行数会大大减少。但是有一个问题。 如果我在开始列和结束列添加另一列代表税率（第一行 6%，第二行 4%）。 MAX / MIN 函数没有多大意义。我们怎样才能克服这一点？谢谢