--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：