问如何为Sql Server行中的一系列常量更改生成序列号

EN

select t.*,
       (case when sender = 'vendor'
             then datediff(second,
                           min(date) over (partition by grp),
                           max(date) over (partition by grp)
                          ) / (24 * 60 * 60.0)
        end) as diff
from (select t.*,
             sum(case when sender = 'Vendor' then 1 else 0 end) over (order by id desc) as grp
      from t
     ) t;

select t.*,
       case when sender = 'Vendor' 
            then DATEDIFF(hour, date, first_value(date) over (partition by rn - rn_s order by date) ) / 24.0 end as diff
  from
(select t.*,
       row_number() over (order by date) as rn,
       row_number() over (partition by sender order by date) as rn_s
  from yout_table t) t