select A.*,'B表数据' as col from #tmp_asset3 A inner join #tmp_asset2 B on A.c_nbr=B.b_nbr
where A.C_nbr=(select max(b_nbr) from #tmp_asset2)
union 
select A.*,'A表数据' as col  from #tmp_asset3 A inner join #tmp_asset1 B on A.c_nbr=B.a_nbr
where A.C_nbr=(select max(a_nbr) from #tmp_asset1)

--再取结果集的第一列,忘了咋写取中间结果集的数据了

------解决方案--------------------
确保只有一条数据的话，union两个结果集，取第一列，这样写应该可以实现，

------解决方案--------------------
SQL code


select top 1 result.* from (
select A.*,'B表数据' as col from #tmp_asset3 A inner join #tmp_asset2 B on A.c_nbr=B.b_nbr
where A.C_nbr=(select max(b_nbr) from #tmp_asset2)
union 
select A.*,'A表数据' as col  from #tmp_asset3 A inner join #tmp_asset1 B on A.c_nbr=B.a_nbr
where A.C_nbr=(select max(a_nbr) from #tmp_asset1)
) result

------解决方案--------------------
这个要求能用last（）函数不能？貌似可以啊

------解决方案--------------------
b表应该可以（我认为）

------解决方案--------------------
max（）函数对datetime类型可不可以用啊

------解决方案--------------------
SQL code

if (object_id('c')is not null) drop table c
create table c
(
c_nbr varchar(50),
c_cur varchar(50),
c_untprc varchar(20),
c_dt datetime
)
insert into c
select 'aa','rmb','1.3','2011-5-6'
union all
select 'bb','usd','1.4','2012-10-1'
union all
select 'cc','cc','usd','2012-10-1'
union all
select 'dd','rmb','22','2012-6-9'

/*
（所影响的行数为 4 行）
*/
if(object_id('b')is  not null) drop table b
create table b
(
b_nbr varchar(20),
b_cur varchar(20),
b_untprc decimal(18,1),
b_dt datetime
)
insert into b
select 'aa','rmb',1.3,'2011-5-6'
union all
select 'bb','usd',1.5,'2012-5-9'
union all
select 'bb','usd',1.4,'2012-10-1'
union all
select 'dd','rmb',21,'2011-12-12'
union all
select 'ee','rmb',24,'2012-4-9'
union all
select 'dd','rmb',22,'2012-6-9'

if(object_id('a') is not null) drop table a
create table a
(
a_nbr varchar(20),
a_cur varchar(20) null,
a_untprc decimal(18,1) null,
a_dt datetime
)
insert into a
select 'aa','rmb',1.2,'2012-10-1'
union all
select 'bb','',0,'2012-10-1'
union all
select 'cc','usd',0.5,'2012-10-1'
union all
select 'dd','',0,'2012-10-1'
union all
select 'ee','',0,'2012-10-1'
union all
select 'ff','',0,'2012-10-1'

alter table a
add id int identity(1,1)
alter table b
add id int identity(1,1)
alter table c
add id int identity(1,1)


select * from a
/*
aa    rmb    1.2    2012-10-01 00:00:00.000    1
bb        .0    2012-10-01 00:00:00.000    2
cc    usd    .5    2012-10-01 00:00:00.000    3
dd        .0    2012-10-01 00:00:00.000    4
ee        .0    2012-10-01 00:00:00.000    5
ff        .0    2012-10-01 00:00:00.000    6
*/
select * from b
/*
aa    rmb    1.3    2011-05-06 00:00:00.000    1
bb    usd    1.5    2012-05-09 00:00:00.000    2
bb    usd    1.4    2012-10-01 00:00:00.000    3
dd    rmb    21.0    2011-12-12 00:00:00.000    4
ee    rmb    24.0    2012-04-09 00:00:00.000    5
dd    rmb    22.0    2012-06-09 00:00:00.000    6

*/
select * from c
/*
aa    rmb    1.3    2011-05-06 00:00:00.000    1
bb    usd    1.4    2012-10-01 00:00:00.000    2
cc    cc    usd    2012-10-01 00:00:00.000    3
dd    rmb    22    2012-06-09 00:00:00.000    4
*/

select d.c_cur,
       case when b.b_untprc is null then a.a_untprc else b.b_untprc end as untprc,
       case when b.b_dt is null then a.a_dt else b.b_dt end as dt from 
(
select c_nbr,c_cur,max(b.id) as id from c left join b on c.c_nbr=b.b_nbr
group by c_cur,c_nbr)as d left join b on d.c_nbr = b.b_nbr and d.id = b.id
                          inner join a on a.a_nbr = d.c_nbr                                   
/*
rmb    1.3    2011-05-06 00:00:00.000
usd    1.4    2