分组取最新记录的SQL如何写？实在不好意思了，没分了。

[gdi_gtk1]

sbid revtime interfacetype value
08312 2007-8-11 11:00:00 7 12.90
08312 2007-8-11 12:00:00 7 12.21
08312 2007-8-11 12:00:00 10 112.90
如上记录，需要按interfacetype分组，然后取出时间最新的每个interfacetype的记录，就上面的记录而言，结果应该是最后两条记录合法。该怎么写？

[fa_ge]

sbid revtime interfacetype value
08312 2007-8-11 11:00:00 7 12.90
08312 2007-8-11 12:00:00 7 12.21
08312 2007-8-11 12:00:00 10 112.90
如上记录，需要按interfacetype分组，然后取出时间最新的每个interfacetype的记录，就上面的记录而言，结果应该是最后两条记录合法。该怎么写？

-----------
select * from t a
where not exists(select 1 from t where interfacetype=a.interfacetype and revtime <a.revtime)

[fa_ge]

select * from t a
where not exists(select 1 from t where interfacetype=a.interfacetype and revtime >a.revtime)

[Limpire]

declare @test table (sbid varchar(10), revtime datetime, interfacetype int, value money)
insert @test
select '08312', '2007-8-11 11:00:00', '7', 12.90 union all
select '08312', '2007-8-11 12:00:00', '7', 12.21 union all
select '08312', '2007-8-11 12:00:00', '10', 112.90

select * from @Test a where revtime in (select top 1 revtime from @Test where interfacetype = a.interfacetype order by revtime desc)

[fa_ge]

create table t

(sbid varchar(10), revtime datetime, interfacetype int, value numeric(12,2))
insert into t
select '08312', '2007-8-11 11:00:00', 7 , 12.90 union all
select '08312', '2007-8-11 12:00:00', 7 , 12.21 union all
select '08312', '2007-8-11 12:00:00', 10, 112.90

select * from t a
where not exists(select 1 from t where interfacetype=a.interfacetype and revtime >a.revtime)

sbid revtime interfacetype value
---------- ------------------------------------------------------ ------------- --------------
08312 2007-08-11 12:00:00.000 7 12.21
08312 2007-08-11 12:00:00.000 10 112.90

(2 row(s) affected)

[Limpire]

declare @test table (sbid varchar(10), revtime datetime, interfacetype int, value money)
insert @test
select '08312', '2007-8-11 11:00:00', '7', 12.90 union all
select '08312', '2007-8-11 12:00:00', '7', 12.21 union all
select '08312', '2007-8-11 12:00:00', '10', 112.90

select * from @Test a where revtime in (select top 1 revtime from @Test where interfacetype = a.interfacetype order by revtime desc)
-- or
select * from @Test a where revtime in (select max(revtime) from @Test where interfacetype = a.interfacetype)

[在路上_-]

select *
from @Test a
where revtime =
(select max(revtime) from @Test where interfacetype =
a.interfacetype)

[qys2000]

create table t

(sbid varchar(10), revtime datetime, interfacetype int, value numeric(12,2))
insert into t
select '08312', '2007-8-11 11:00:00', 7 , 12.90 union all
select '08312', '2007-8-11 12:00:00', 7 , 12.21 union all
select '08312', '2007-8-11 12:00:00', 10, 112.90

select * from t a
where not exists(select 1 from t where interfacetype=a.interfacetype and revtime >a.revtime)