oracle中，-根据B表的新部门更改A表的旧部门

create table A
(
BADEPTID VARCHAR2(30) not null, --旧部门编码
ID NUMBER not null
);
alter table A
add constraint ID_PK primary key (ID);


create table B
(
OLD_DEPT VARCHAR2(4000) not null,--旧部门编码
NEW_DEPT VARCHAR2(200) not null --新部门编码
);
alter table B
add constraint TEMP_PK primary key (OLD_DEPT, NEW_DEPT);


--根据B表的新部门更改A表的旧部门
Update A aa
Set aa.badeptid = (Select ab.new_dept From B ab Where ab.old_dept = aa.badeptid)
Where Exists (Select 1 From B ab Where ab.Old_dept = aa.badeptid);