Oracle8i的左连接问题

Question

放里面行不？A.fld1=substr(B.fld1(+),1,2);

Answer 1

select A.fld1,
       B.* 
from haha A ,(select * from haha where fld2='hehe' ) B
where A.fld1=substr(B.fld1(+),1,2); 

Answer 2

或：
 
select A.fld1,
       B.* 
from haha A left join 
(select * from haha where fld2='hehe' ) B
where A.fld1=substr(B.fld1,1,2); 

Answer 3

更正：
select A.fld1,
       B.* 
from haha A left join 
(select * from haha where fld2='hehe' ) B
on A.fld1=substr(B.fld1,1,2);

Answer 4

select A.fld1,
       B.* 
from haha A ,(select * from haha where fld2='hehe' ) B
where A.fld1(+)=substr(B.fld1,1,2);