查询SQL强化练习

-- 1 列出至少有一个员工的所有部门
select *
  from dept
 where deptno in
       (select deptno from emp group by deptno having count(empno) >= 1);

-- 2 列出薪金比“SMITH”多的所有员工
select * from emp where sal > (select sal from emp where ename = 'SMITH');

-- 3 列出所有员工姓名及其直接上级的姓名
select e1.ename, e2.ename from emp e1, emp e2 where e1.mgr = e2.empno(+);

-- 4 列出受雇日期早于其直接上级的所有员工的编号，姓名，部门名称
select e1.empno, e1.ename, d.dname, d.loc
  from emp e1, emp e2, dept d
 where e1.mgr = e2.empno
   and e1.deptno = d.deptno
   and e1.hiredate < e2.hiredate;

-- 5 列出部门名称和这些部门的员工信息，同时列出那些没有员工的部门
select d.deptno, d.dname, d.loc, e.*
  from emp e, dept d
 where e.deptno(+) = d.deptno;

-- 6 列出最低薪金大于1500的各种工作及从事此工作的全部雇员人数
select job, count(empno) from emp group by job having min(sal) > 1500;

-- 7 列出在部门“SALES”(销售部)工作的员工姓名，假定不知道销售部的部门编号
select *
  from emp
 where deptno = (select deptno from dept t where dname = 'SALES');
select e.*
  from emp e, dept d
 where e.deptno = d.deptno
   and d.dname = 'SALES';

-- 8 列出薪金高于公司平均薪金所有员工，所在部门，上级领导，公司的工资等级
select e1.empno, e1.ename, d.dname, e1.sal, sg.grade
  from emp e1, emp e2, dept d, salgrade sg
 where e1.sal > (select avg(sal) from emp)
   and e1.mgr = e2.empno
   and e1.deptno = d.deptno
   and e1.sal between losal and hisal;

-- 9 列出与scott从事相同工作的所有员工及部门名称
select e.empno, e.ename, d.dname
  from emp e, dept d
 where e.deptno = d.deptno
   and e.job = (select job from emp where ename = 'SCOTT');

-- 10 列出薪金等于部门30中员工的薪金的所有员工的姓名和薪金
select ename, sal
  from emp
 where sal = any (select sal from emp where deptno = 30);

select ename, sal
  from emp
 where sal in (select sal from emp where deptno = 30);

-- 11 列出薪金高于在部门30工作的所有员工的薪金的员工姓名和薪金，部门名称
select ename, sal, dname
  from emp, dept
 where emp.deptno = dept.deptno
   and sal > all (select sal from emp where deptno = 30);

-- 12 列出在每个部门工作的员工数量，平均工资和平均服务年限
select deptno,
       count(1) 员工数量,
       avg(sal) 平均工资,
       avg((sysdate - hiredate) / 365) 平均服务年限
  from emp
 group by deptno;

-- 13 列出所有部门的详细和部门人数
select d.deptno, d.dname, d.loc, count(e.empno)
  from dept d, emp e
 where d.deptno = e.deptno
 group by d.deptno, d.dname, d.loc;

-- 14 列出所有员工的姓名，部门名称和工资
select e.ename, d.dname, e.sal
  from emp e, dept d
 where e.deptno = d.deptno;

-- 15 列出各种工作的最低工资及从事此工作的员工姓名
select e2.job, e2.min_sal, e1.ename
  from emp e1, (select job, min(sal) min_sal from emp group by job) e2
 where e1.job = e2.job
   and e1.sal = e2.min_sal;

-- 16 列出各部门的经理的最低薪金
select deptno, min(sal) from emp where job = 'MANAGER' group by deptno;

-- 17 列出所有员工的年工资，按年薪从低到高排序(注意对奖金的处理)
select empno, ename, sal * 12 + nvl(comm, 0) from emp order by 3 asc;

-- 18 检索出某个员工的上级主管，并要求这些主管的薪水不小于3000
select e1.ename, e2.ename, e2.sal
  from emp e1, emp e2
 where e1.mgr = e2.empno
   and e2.sal >= 3000;

-- 19 求出部门名称中，带‘S’字符的部门员工，工资合计，部门人数
select deptno, sum(sal), count(empno)
  from emp
 where deptno in (select deptno from dept t where dname like '%S%')
 group by deptno;

-- 20 给任职超过10年的员工加薪10%
update emp set sal = sal * (1 + 0.2) where (sysdate - hiredate) / 365 > 10;