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Á·Ï°:
  drop  table  Employee;
create  table    Employee(
                 id         number    primary key,
                 uName      varchar2(32) ,
                 dept_id   int ,
                 salary      number
                );
insert into   Employee (id ,uName, dept_id, salary ) values (1,'ZhangShan',null, 10000);
insert into   Employee (id ,uName, dept_id, salary ) values (2,'LiShi',1, 8000);
insert into   Employee (id ,uName, dept_id, salary ) values (3,'WangWu',2, 6000);
insert into   Employee (id ,uName, dept_id, salary ) values (4,'ZhaoLiu',3, 4000);
insert into   Employee (id ,uName, dept_id, salary ) values (5,'QianQi',4, 2000);
񻂗:
   <1>ʹÓÃ×ÔÁ¬½Ó²é³ö±íÖÐÔ±¹¤µÄÐÕÃû¼°ÆäÁìµ¼µÄÐÕÃû?
select a.ename,b.ename
from emp a inner join emp b
on a.mgr = b.empno ;
   <2>ʹÓÃÍâÁ¬½Ó²é³ö±íÖÐÔ±¹¤µÄÐÕÃû¼°ÆäÁìµ¼µÄÐÕÃû?
select a.ename,b.ename
from emp a inner join emp b
on a.mgr =b.empno(+) ;
   <3> ÓÃÒ»ÌõSQLÓï¾äʵÏÖ
        ¸ø 2 ²¿ÃÅÔ±¹¤½«¹¤×ʽµÖÁÔ­À´ 80%
        ¸ø 4 ²¿ÃÅÔ±¹¤½«¹¤×ʼõÖÁÔ­À´ 70% 
        ¸ø 1 3 5  ²¿ÃÅÔ±¹¤½«¹¤×ÊÕÇÖÁÔ­À´ 150%
    
 update emp set sal=decode(deptno,10,0.8*sal,20,0.7*sal,30,1.5*sal) ;  
    
 &nbs