postgreSQL 数据库基础 row_number() 与distinct用法说明

我就废话不多说了，大家还是直接看代码吧~

select count(s.*)
from (
select *, row_number() over (partition by fee_date order by fee_date) as gr
from new_order where news_id=’novel’ and order_status=’2′
) s
where s.gr = 1
SELECT count(DISTINCT fee_date) as dis from new_order where news_id=’novel’ and order_status=’2′