amazon-web-services - 如何在AWS Athena中使用LISTAGG？

Question

我想使用LISTAGG在Amazon Athena中进行查询。
有什么方法可以将数据聚合到列表或字符串中？

作为Amazon Athena User Guide，

The grouping_expressions element can be any function (such as SUM, AVG, COUNT, etc.)

Answer 1

选项1:数组

with t(i) as (select 1 union all select 2 union all select 3) 
select  array_agg(i) as result 
from    t
;

  result
-----------
 [3, 2, 1]

选项2:字符串

with t(i) as (select 1 union all select 2 union all select 3) 
select  array_join(array_agg(i),',') as result 
from    t
;

 result
--------
 1,3,2