如何在 HIVE 中从长结构变为宽结构？

Question

我有一个如下所示的配置单元数据data in long format

我想将其重组为如下所示 data in wide format

我的看起来像这样my latest attempt

这是我用过的代码。我想去掉所有的 NULL，并将所有月份合并为一年下的一行。

select carrier, year, month,

max(case when month =1 then quantity end) as jan,
max(case when month =2 then quantity end) as feb,
max(case when month =3 then quantity end) as mar,
max(case when month =4 then quantity end) as apr,
max(case when month =5 then quantity end) as may,
max(case when month =6 then quantity end) as jun,
max(case when month =7 then quantity end) as jul,
max(case when month =8 then quantity end) as aug,
max(case when month =9 then quantity end) as sep,
max(case when month =10 then quantity end) as oct,
max(case when month =11 then quantity end) as nov,
max(case when month =12 then quantity end) as dec

from (select final_month.*, row_number() over 
(partition by carrier, year order by carrier, year) from final_month) 
final_month group by carrier, year, month;

这是我一直在使用的所有参考资料 link link

谢谢！

Answer 1

从 select 中删除 month 并分组。我相信你想要 SUM，而不是 max()，但你当然更了解数据：

select carrier, year, 
sum(case when month =1 then quantity end) as jan,
sum(case when month =2 then quantity end) as feb,
sum(case when month =3 then quantity end) as mar,
sum(case when month =4 then quantity end) as apr,
sum(case when month =5 then quantity end) as may,
sum(case when month =6 then quantity end) as jun,
sum(case when month =7 then quantity end) as jul,
sum(case when month =8 then quantity end) as aug,
sum(case when month =9 then quantity end) as sep,
sum(case when month =10 then quantity end) as oct,
sum(case when month =11 then quantity end) as nov,
sum(case when month =12 then quantity end) as dec
from ...
group by carrier, year

如何在 HIVE 中从长结构变为宽结构？

How to go from long to wide structure in HIVE?

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