在 Oracle Sql 中的 Select 语句中根据条件排除和包含列标题

Posted 2023-03-24

【中文标题】在 Oracle Sql 中的 Select 语句中根据条件排除和包含列标题

【英文标题】：Exclude and Include column header based on condition in Select statement in Oracle Sql

【发布时间】：2016-07-08 05:33:02

【问题描述】：

我有一张表，其架构如下

Documentno  created      docstatus
498461      08-OCT-14    IN
501681      27-OCT-14    IN
544491      19-AUG-15    IP
550041      28-SEP-15    IP

输出应该是像

这样的格式

select Documentno, created from c_order where docstatus in ('IP')
Documentno  created      
544491      19-AUG-15    
550041      28-SEP-15    

select Documentno, created,docstatus from c_order where docstatus in ('IN')
Documentno  created      docstatus
498461      08-OCT-14    IN
501681      27-OCT-14    IN

联合的预期输出

  Documentno     created      
    544491      19-AUG-15    
    550041      28-SEP-15   
  Documentno   created       docStatus
    498461      08-OCT-14    IN
    501681      27-OCT-14    IN

这可能在 sql select 语句中吗？ 我尝试过使用 Case 但它仅适用于 Value 不适用于列名 请任何人指导我如何在 oracle 中实现此 select 语句？

【参考方案1】：

你必须给出列名，至少它应该由一个字符组成

测试数据

with t(Documentno,
created,
docstatus) as
 (select 498461, sysdate, 'IN'
    from dual
  union all
  select 501681, sysdate + 1, 'IN'
    from dual
  union all
  select 544491, sysdate + 2, 'IP'
    from dual
  union all
  select 550041, sysdate + 3, 'IP'
    from dual)

查询

  select Documentno, created, null as " "
      from t
     where docstatus in ('IP')
    union all
    select null, null, 'STATUS'
      from dual
    union all
    select Documentno, created, docstatus from t where docstatus in ('IN')

输出

DOCUMENTNO CREATED
---------- -------- ------
    544491 10/07/16
    550041 11/07/16
                    STATUS
    498461 08/07/16 IN
    501681 09/07/16 IN