相关子查询在 Netezza 中不起作用

问题描述

我在 Netezza 中有一个这样的查询，但不确定如何重写它以使其有效。谢谢

with dates as (
      select distinct event_date from table
     )
select event_date,(select count(distinct id)
        from table 
        where event_date < dates.event_date
       )
from dates

This form of correlated query is not supported - consider rewriting

解决方法

无论如何，使用窗口函数会更有效。我认为逻辑是：

select event_date,sum(count(*)) over (order by event_date) - count(*) as events_before
from table
group by event_date