求问关于表自连接的问题

Question

大家好我想问下oracle的表自连接的问题，有一张emp表，想显示员工ford的上级，设定worker.emp和boss.emp我写的pl/sql语句是select worker.ename,boss.ename from worker.emp "员工"，boss.emp "上级" where worker.mgr=boss.empno and worker.ename="ford"； 提示我为无效的sql语句，我是菜鸟，哪位大侠帮我看看问题出在哪里？

Answer 1

这个是表结构
EMPNO ENAME                          JOB                              MGR HIREDATE          SAL      COMM DEPTNO
----- ------------------------------ ------------------------------ ----- ----------- --------- --------- ------
    1 xiaoming                       salesman                           2 2011/3/3      2500.00   1500.00     20
  369 SMITH                          CLERK                            902 1980/12/17     800.00               20
  499 ALLEN                          SALESMAN                         698 1981/2/20     1600.00    300.00     30
  521 WARD                           SALESMAN                         698 1981/2/22     1250.00    500.00     30
  566 JONES                          MANAGER                          839 1981/4/2      2975.00               20
  654 MARTIN                         SALESMAN                         698 1981/9/28     1250.00   1400.00     30
  698 BLAKE                          MANAGER                          839 1981/5/1      2850.00               30
  782 CLARK                          MANAGER                          839 1981/6/9      2450.00               10
  788 SCOTT                          ANALYST                          566 1987/4/19     3000.00               20
  839 KING                           PRESIDENT                            1981/11/17    5000.00               10
  876 ADAMS                          CLERK                            788 1987/5/23     1100.00               20
  900 JAMES                          CLERK                            698 1986/12/12     950.00               30
  902 FORD                           ANALYST                          566 1981/12/3     3000.00               20
  369 SMITH                          CLERK                           7902 1980/12/17     800.00    100.00     20

Answer 2

问题解决了
select a.ename worker ,b.ename boss from emp a,emp b where a.mgr=b.empno and a.ename='FORD';
没人鸟我