请问一SQL语句:
请问一SQL语句: 
 有表T1,T2 
 T1有如下2列 
 C1	C2 
 PA	1 
 PA	2 
 PA	3 
 PB	1 
 PB	2 
 PB	4 
 T2有如下3列 
 C1	C2	C3 
 PA	1 
 PA	3 
 PB	1 
 PB	2 
 PB	3 
 现在要将表T1中不在表T2中的记录插入表T2中,请问SQL语句怎么写?谢谢!
------解决方案--------------------INSERT INTO T2 ( C1, C2 ) 
 SELECT A.C1, A.C2 
 FROM T1 as A  
     left join T2 as B on A.C1=B.C1 and A.C2=B.C2 
 where isnull(B.C1) or isnull(B.C2)     
 --或者     
 INSERT INTO T2 ( C1, C2 ) 
 SELECT C1, C2 
 FROM T1  
 where C1 & C2 NOT in (select C1 & C2 from T2)