问题描述
我想知道 bigquery 标准 sql 中的前导窗口函数是否有任何解决方法可以使用表值而不是文字或查询参数?
select
artcl,days,lead(days,ofst)over(partition by artcl order by days) as tst
from(
select 123 as artcl,1 as days,2 as ofst
union all
select 123 as artcl,2 as days,3 as days,2 as ofst
)
解决方法
您可以使用以下方法
select artcl,days,ofst,arr[safe_offset(row_number() over(partition by artcl order by days) + ofst - 1)] as tst
from `project.dataset.table`
join (
select artcl,array_agg(days order by days) arr,from `project.dataset.table`
group by artcl
)
using(artcl)