if object_id('TESTA')is not null  drop table TESTA
if object_id('TESTB') is not null drop table TESTB

create table TESTA
(
recdate smalldatetime,
rmk nvarchar(100)
)
create table TESTB
(
recdate smalldatetime,
rmk nvarchar(100)
)

insert TESTA
select '2012-09-01','A中第一條'
union select '2012-09-01','A中第二條'
union select '2012-09-02','A中第三條'
union select '2012-09-02','A中第四條'
union select '2012-09-02','A中第五條'
union select '2012-09-02','A中第六條'

insert TESTB
select '2012-09-01','B中第一條'
union select '2012-09-01','B中第二條'
union select '2012-09-01','B中第三條'
union select '2012-09-01','B中第四條'
union select '2012-09-01','B中第五條'
union select '2012-09-02','B中第六條'
union select '2012-09-02','B中第七條'
union select '2012-09-02','B中第八條'

;with cet1 as(select *,row_number()over(partition by recdate order by rmk) rn from testa
),
CET2 as(select *,row_number()over(partition by recdate order by rmk) rn from testb)
select isnull(a.recdate, b.recdate) recdate,
isnull(a.rmk, b.rmk) [a.rmk],case when a.rmk is null then '' else isnull(b.rmk, '') end [b.rmk]
 from cet1 a full outer join cet2 b on a.recdate = b.recdate and a.rn = b.rn
/*recdate                 a.rmk      b.rmk
----------------------- -------------------------
2012-09-01 00:00:00     A中第1條      B中第1條
2012-09-01 00:00:00     A中第2條      B中第2條
2012-09-01 00:00:00     B中第3條      
2012-09-01 00:00:00     B中第4條      
2012-09-01 00:00:00     B中第5條      
2012-09-02 00:00:00     A中第3條      B中第6條
2012-09-02 00:00:00     A中第4條      B中第7條
2012-09-02 00:00:00     A中第5條      B中第8條
2012-09-02 00:00:00     A中第6條      

(9 行受影响)
*/