如何在 Informix 12.10 中将行转换为列

Question

Localcol	SA_Device A	SA_Device B	SA_Device C
2021-05-04 21:27:40	12	13	14
2021-05-04 21:28:00	16	17	18

Localcol	AA_Device A	AA_Device B
2021-05-04 21:27:40	34	43
2021-05-04 21:28:00	45	46

我需要将这 2 个表合并为一个表并按以下格式显示。

Localcol	Device	SA	AA
2021-05-04 21:27:40	Device A	12	34
2021-05-04 21:27:40	Device B	13	43
2021-05-04 21:27:40	Device C	14	NA
2021-05-04 21:28:00	Device A	16	45
2021-05-04 21:28:00	Device B	17	46
2021-05-04 21:28:00	Device C	18	NA

请帮我在 Informix 12.10 中解决这个问题。

Answer 1

嗯。 . .我认为你应该取消每个 table 的旋转，然后加入它们：

select coalesce(t2.localcol, t1.localcol) as localcol,
       coalesce(t2.device, t1.device) as device,
       t1.SA, t2.AA
from (select Localcol, 'A' as device, AA_Device_A as AA
      from table2 t2
      union all
      select Localcol, 'B' as device, AA_Device_B
      from table2 t2
     ) t2 full join
     (select Localcol, 'A' as device, SA_Device_A as SA
      from table2 t1
      union all
      select Localcol, 'B' as device, SA_Device_B as SA
      from table2 t1
      union all
      select Localcol, 'C' as device, SA_Device_B as SA
      from table2 t1
     ) t1
     on t1.localcol = t2.localcol and t1.device = t2.device

如何在 Informix 12.10 中将行转换为列

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