select
a.ID,
a.[Date],
a.p_Data-(select p_Data from 電量數據表 where ID=a.ID and datediff(dd,[Date],a.[Date])=1)
from
電量數據表 a
where
exists(select 1 from 電量數據表 where ID=a.ID and datediff(dd,[Date],a.[Date])=1)
a.ID,
a.[Date],
a.p_Data-(select p_Data from 電量數據表 where ID=a.ID and datediff(dd,[Date],a.[Date])=1)
from
電量數據表 a
where
exists(select 1 from 電量數據表 where ID=a.ID and datediff(dd,[Date],a.[Date])=1)
from a a,a b--两表一样
where a.Date= b.Date-1
from a a,a b --两表一样
where a.Date= b.Date-1
group by a.ID ,a.Date--应该可以吧
from tb a, tb b
where a.id=b.id
and a.Date= b.Date-1
from tb a, tb b
where a.id=b.id
and a.Date= b.Date-1