选择Impala中的stack（）UDTF

Question

在Hive中，我可以使用stack（）UDTF这样采样数据：

with students as ( 
select stack(5,
1,'Vikrant',
2,'Abhishek',
3,'Ragesh',
4,'Valeriy',
5,'Swarna') as (id, name)
)

select * from students;

在Presto I can use values中相同。

如何使用multiple selects for each row and UNION ALL like in this answer在Impala EXCEPT中做到这一点？

Answer 1

根据我的研究，Impala尚不支持表生成功能。很遗憾，Impala中没有堆栈，no lateral view explode，no UDTF are possible。

所以，唯一的方法是这样：

with students as ( 
select 1 as id,'Vikrant'  as name union all
select 2 as id,'Abhishek' as name union all
select 3 as id,'Ragesh'   as name union all
select 4 as id,'Valeriy'  as name union all
select 5 as id,'Swarna'   as name
)

select * from students;