1：列出所有员工的姓名，部门名称，和工资

select a1.ename,a1.sal,a2.dname from emp a1,dept a2 where a1.deptno = a2.deptno;

2：列出所有部门的详细信息和部门人数

select a2.deptno,a2.dname,a2.loc,count(a1.empno) from emp a1,dept a2 where a1.deptno(+) = a2.deptno group by a2.deptno,a2.dname,a2.loc;

3：列出所有员工的年工资，所在部门名称，按年薪升序排列

select a1.sal*12 ,a2.dname from emp a1,dept a2 where a1.deptno = a2.deptno order by a1.sal*12;

4：查出每个员工的上级主管及所在部门名称，并要求这些主管的薪水超过3000

select employee.ename,boss.ename ,a1.dname from emp employee,emp boss,dept a1 where employee.mgr = boss.empno and boss.deptno = a1.deptno and boss.sal >3000;

5：求出部门名称中带’S’字符的部门员工的工资合计，部门人数

SELECT d.deptno,NVL(SUM(sal),0),COUNT(empno)FROM emp e,dept d WHERE e.deptno(+)=d.deptno AND d.dname LIKE '%S%' GROUP BY d.deptno ;

6：列出部门名称和这些部门的员工信息（数量，平均工资），同时列出那些没有员工的部门

select d.dname,avg(e.sal),count(e.empno) from emp e,dept d where e.deptno(+)=d.deptno group by d.dname;

7：列出在部门”SALES”工作的员工姓名，基本工资，雇用日期，部门名称，假定不知道销售部的部门编号

select a1.ename,a1.sal,a1.hiredate,a2.dname from emp a1,dept a2 where a1.deptno = a2.deptno and a2.dname = 'SALES';

8：列出公司各个工资等级雇员的数量，平均工资

select grade,count(*),avg(sal) from emp, salgrade where sal between losal and hisal group by grade;

9：列出薪水高于在部门30工作的所有员工的薪金的员工姓名和薪金，部门名称

select a1.ename,a1.sal,a2.dname from emp a1, dept a2 where a1.deptno = a2.deptno and sal > all(select sal from emp where deptno = 30);

10：列出受雇日期早于直接上级的所有员工的编号，姓名，部门名称，部门位置，部门人数

SELECT e.empno,e.ename,d.dname,d.loc,temp.count

FROM emp e,emp m,dept d,(

     SELECT deptno dno, COUNT(empno) count

     FROM emp

     GROUP BY deptno) temp

WHERE e.mgr = m.empno(+) AND e.hiredate < m.hiredate

AND e.deptno = d.deptno

AND e.deptno = temp.dno;

11：列出所有“clerk”的姓名及其部门名称，部门人数，工资等级

SELECT e.ename , d.dname ,temp.count,s.grade

FROM emp e, dept d,(

     SELECT deptno dno,COUNT(empno) count

     FROM emp

     GROUP BY deptno) temp,salgrade s

WHERE job='CLERK'

AND e.deptno = d.deptno

AND d.deptno = temp.dno

AND e.sal BETWEEN s.losal AND s.hisal;