透视 2 行 bigquery

Question

如何将 2 行旋转成列？

ID|col_1|col_2|col_3|col_4
1 |a    |A    |Q    |5000
1 |a    |B    |Q    |8000
2 |a    |A    |R    |4000
2 |a    |B    |T    |6000

进入：

ID|col_1|A_col3|A_col4|B_col3|B_col4
1 |a    |Q     |5000  |R     |4000
2 |a    |Q     |8000  |T     |6000

col_2 中的值现在是列标题，col_3 和 col_4 中的值是主元中的放大值。

我试过了，但坚持下一步，没有给出想要的结果：

select * from 
(
  select ID, col_1, col_2, col_3, col_4 from tableA
) as A
pivot (max(col_3) for col_2 in ('A','B'))

Answer 1

只使用条件聚合：

select id,
       max(case when col_2 = 'A' then col_3 end) as a_col3,
       max(case when col_2 = 'A' then col_4 end) as a_col4,
       max(case when col_2 = 'B' then col_3 end) as b_col3,
       max(case when col_2 = 'B' then col_4 end) as b_col4
from tablea
group by id;

Answer 2

I tried this but stuck on the next step ...

考虑以下方法

select *
from tableA
pivot (max(col_3) as col3, max(col_4) as col4 for col_2 in ('A', 'B'))

如果应用于您问题中的示例数据 - 输出为

透视 2 行 bigquery

Pivot 2 rows bigquery

pivot

google-bigquery