Question

Oracle 查询列出员工的姓名及其上级的姓名

EMPNO ENAME JOB MGR
7369 SMITH CLERK 7902
7499 ALLEN SALESMAN 7698
7521 WARD SALESMAN 7698
7566 JONES MANAGER 7839
7654 MARTIN SALESMAN 7698
7698 BLAKE MANAGER 7839
7782 CLARK MANAGER 7839
7788 SCOTT ANALYST 7566
7839 KING PRESIDENT
7844 TURNER SALESMAN 7698
7876 ADAMS CLERK 7788
7900 JAMES CLERK 7698
7902 FORD ANALYST 7566
7934 MILLER CLERK 7782
EMPNO是员工号，ENAME是员工名，MRG是上级编号
求各位大神解答

Answer 1

select a.ename 员工名字,b.ename 上级名字 from emp a,emp b where a.mgr=b.empno(+)

Answer 2

select * from 员工表 where 部门编号=(select 部门编号 from 部门表 where 部门名称='查询的部门名称')；

Answer 3

用start with connect by 会更好吧

Answer 4

select a.empno,a.ename,b.empno,b.enam from emp a left join emp b on a.mgr=b.empno