如何编写将电话号码从列转换为单个列的SQL查询？

如何编写将电话号码从列转换为单个列的SQL查询。假设有多个personID，每个personID最多有3种电话类型，主要、次要和第三。目前，对于每个人，他们被列在三个单独的列中

理想的结果是电话号码都在一列中，而另一列包含电话类型

当前数据

个人识别码 主电话 辅助电话 第三方电话 1. 2221111111 5551111111 9991111111 2. 2221111112 5551111112 9991111112 3. 2221111113 5551111113 9991111113 4. 2221111114 5551111114 9991111114

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在Oracle 12c版的起始版本中，您可以使用

交叉应用

：

select t.person_id, x.*
from mytable t
cross apply (
    select primary_phone as phone_number, 'Primary' as phone_type from dual
    union all select secondary_phone, 'Secondary' from dual
    union all select tertiary_phone, 'Tiertiary' from dual
) x

在早期版本中，您可以使用

union all

：

select person_id, primary_phone as phone_number, 'Primary' as phone_type from mytable
union all select person_id, secondary_phone, 'Secondary' from mytable
union all select person_id, tertiary_phone, 'Tiertiary' from mytable

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您似乎想执行

unpivot

with p as (
  select 1 person_id, 
         '2221111111' primary_phone, 
         '5551111111' secondary_phone, 
         '9991111111' tertiary_phone
    from dual
  union all
  select 2, 
         '2221111112' primary_phone, 
         '5551111112' secondary_phone, 
         '9991111112' tertiary_phone
    from dual
)
select person_id,
       phone_number,
       phone_type
  from p
unpivot (
  phone_number
  for phone_type in (
     primary_phone as 'Primary',
     secondary_phone as 'Secondary',
     tertiary_phone as 'Tertiary'
  )
)

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A显示正在运行的查询

非常感谢。无论哪种选择都会很有帮助谢谢。。。