有興趣的變量（紅移）

Question

行第一行： - 最新 - 城市 - 交付

如何退還在每個城市的首次傳遞的表？

Answer 1

我認爲這redshift支持row_number：

select * 
from (
    select date, city, delivery, 
      row_number() over (partition by city order by date desc) rn 
    from yourtable 
) t 
where rn = 1 

• http://docs.aws.amazon.com/redshift/latest/dg/r_WF_ROW_NUMBER.html