with C as
(
select ID,
row_number() over(order by DT) as rn
from YourTable
)
delete C1
from C as C1
inner join C as C2
on C1.rn = C2.rn-1 and
C1.ID = C2.ID
with C as
(
select ID,
row_number() over(order by DT) as rn
from YourTable
)
delete C1
from C as C1
inner join C as C2
on C1.rn = C2.rn-1 and
C1.ID = C2.ID