insert into t2(id,title,link,addtime)
select t1.id,t1.title,t1.link,t1.addtime
from t1 left join t2 on t1.title=t2.title and t1.link=t2.link
where t2.id is null

------解决方案--------------------

SQL code

有两两张表t1   t2结果相同   
结构 
t1 
id   Title   Link   AddTime 
t2 
id   Title   Link   AddTime 
--------------------------

insert into t2 select * from t1 a
where not exists(select 1 from t2 where title=a.title and link=a.link)