如何根据某些特定条件更新表？

Question

我有一张桌子，如下所示。

我希望将其更新到下面。

基本上，根据A_ID<>0 and B_ID<>0, C_ID=0的记录，如果他们的相应记录具有相同的A_ID and B_ID，而C_ID<>0（在这种情况下为A_ID=1001 and A_ID=1002），请设置{{ 1}}，IsCurrent=0到相应的ActiveTo。

由于

Answer 1

嗯。嗯。 。 。您可以将记录标识为：

select t.*
from (select t.*,
             lead(ActiveFrom) over (partition by a_id, b_id order by c_id) as next_ActiveFrom
      from t
     ) t
where c_id = 0 and next_ActiveFrom is not null;

然后更新它们：

with toupdate as (
      select t.*
      from (select t.*,
                   lead(ActiveFrom) over (partition by a_id, b_id order by c_id) as next_ActiveFrom
            from t
           ) t
      where c_id = 0 and next_ActiveFrom is not null
     )
update toupdate
    set isactive = 0,
        activeTo = dateadd(second, -1, next_ActiveFrom);