--创建表A,B：
create table A (a1 varchar2(33),a2 varchar2(33),a3 varchar2(33));
create table B (b1 varchar2(33),b2 varchar2(33),b3 varchar2(33));
--插入数据
insert into A values('1','aa','100');
insert into A values('2','bb','100');
insert into A values('3','cc','');
insert into A values('4','dd','200');
insert into B values('1','XX','10000');
insert into B values('2','YY','10000');
insert into B values('4','ZZ','20000');
insert into B values('5','KK','');
commit;
--更新前的表A,B：
--对表A的a2，a3进行更新（带条件）；
update A
set (A.a2,A.a3) =(select B.b2,b.b3
from B
where B.b1= A.a1 and A.a3=100
)
where exists
(select 'X' from B where B.b1=A.a1 and A.a3=100) ;
commit;
--或者：
update A
set (A.a2,A.a3 )=
(select B.b2,b.b3
from B
where B.b1= A.a1 and A.a3=100
)
where (A.a1) in (select
B.b1 from B
where B.b1 = A.a1
and A.a3 =100
);
commit;
--更新后的表A：
