SQL移调和组一些列

Question

我要转和组一些列来自：

Agent  Date  Interval  EmailTime  PhoneTime 
John  1-1-2017 00:00  00:15:00  NULL 
John  1-1-2017 00:15  00:10:00  00:05:00 
John  1-1-2017 00:30  NULL   00:15:00 

要：

Agent  Date  Interval  State   Duration 
John  1-1-2017 00:00  EmailTime  00:15:00 
John  1-1-2017 00:15  EmailTime  00:10:00 
John  1-1-2017 00:15  PhoneTime  00:05:00 
John  1-1-2017 00:30  PhoneTime  00:05:00 

有什么建议？

Answer 1

你不需要一个支点。它可以通过联合所有查询来实现。

Select Agent, Date, Interval 'EmailTime' State, EmailTime  from table where EmailTime is not null 
union all 
Select Agent, Date, Interval 'PhoneTime' State, PhoneTime  from table where PhoneTime is not null 

Answer 2

您可以使用此代码块，旋转：

select agent ,date ,interval 'EmailTime' as state ,emailtime as duration from table where emailtime is not null union all select agent ,date ,interval 'PhoneTime' as state ,phonetime as duration from table where phonetime is not null union all select agent ,date ,interval 'NULL' state ,phonetime as duration from table where emailtime is null and phonetime is null