带过滤器的SQL max和min日期

Question

以下帐户于2014年1月19日关闭,然后在2/27/2018重新开放,然后在3/26/2018再次关闭.如何在打开和关闭此帐户时编写要捕获的sql.closerestrictind ='C'是帐户关闭的时间.

我们正在数据仓库中工作,每天都会加载数据以捕获所有历史记录.

对于acct 1234,它应该是这样的:

closed on 1/19/2018
re-opened on 2/27/2018
closed on 3/26/2018

谢谢!

Answer 1

你可以使用lag():

select acctnbr, effectivedate,
       (case when closerestrictedind = 'C' then 'closed' else 'opened' end) as action
from (select t.*, lag(closerestrictedind) over (partition by acctnbr order by effectivedate) as prev_cr
      from t
     ) t
where prev_cr <> closerestrictedind;