Oracle基礎——簡單查詢練習（一）

練習基於Oracle數據庫中SCOTT用戶下的emp表

1. 查詢scott用戶下的全部表

select * from tabs;

1. 查詢僱員表中的所有信息

select * from emp;

1. 查詢僱員編號，姓名，工做，工資。

select empno,ename,job,sal from emp;

1. 查詢僱員編號，姓名，工做，工資，列表標題需中文顯示。

SELECT empno "僱員編號",ename "僱員姓名" ,job "工做",sal "工資" from emp;

1. 查詢僱員工做種類。

select distinct job from emp;

1. 查詢全部僱員編號,姓名,工做.按如下格式顯示:編號:7369-姓名:SMITH-工做:CLERK (返回一個列)

select  '編號：' || empno || '-姓名：' || ename || '-工做：' || job as 詳情 from emp;

1. 查詢僱員編號,姓名,工做,年薪

select empno,ename,job,(sal + nvl(comm,0))*12 YearlySalary from emp;

1. 查詢工資大於1500的僱員全部信息

select * from emp where sal >1500;

1. 查詢能夠獲得獎金的僱員的名字與獎金

select ename,comm from emp where NVL(comm,0)>0;

select ename,comm from emp where DECODE(comm,null,0,comm) > 0;

1. 查詢工資大於1500或能夠獲得獎金的僱員

select ename from emp where sal > 1500 or nvl(comm,0) > 0;

select ename from emp where sal > 1500 or DECODE(comm,null,0,comm) > 0;

1. 查詢工資大於1500而且能夠領取獎金的僱員

select ename from emp where sal > 1500 and nvl(comm,0) > 0;

select ename from emp where sal > 1500 and DECODE(comm,null,0,comm) > 0;

1. 查詢工資不大於1500或者不能夠領取獎金的僱員

select ename from emp where sal <= 1500 or nvl(comm,0) = 0;

1. 查詢工資在1500到3000的全部僱員信息

select * from emp where sal >=1500 and sal <= 3000;

1. 查詢系統當前時間

select sysdate from dual;

1. 查詢在1981年僱用的員工信息

select * from emp where hiredate like '%81%';

select * from emp where to_char(hiredate,'YYYY') = '1981';

select * from emp where hiredate <= to_date('1981-12-31','YYYY-mm-dd') and hiredate >= to_date('1981-01-01','YYYY-mm-dd');

select * from emp where hiredate between to_date('1981-01-01','YYYY-mm-dd') and to_date('1981-12-31','YYYY-mm-dd');

1. 查詢僱員姓名中第三個字母爲」A」的僱員信息

select * from emp where ename like '__A%';

1. 查詢僱員編號爲7369的僱員信息

select  * from emp where empno = '7369';

1. 查詢僱員編號不爲7369的僱員信息

select  * from emp where empno != '7369';

select  * from emp where empno <> '7369';

1. 查詢編號是7369,7900的僱員信息

select * from emp where empno in (7369,7900);

1. 查詢編號不是7369,7900的僱員信息

select * from emp where empno not in (7369,7900);

1. 查詢僱員信息,按工資由低到高排序

select * from emp order by sal;

select * from emp order by sal asc;

1. 查詢僱員信息,按工資由高到低排序

select * from emp order by sal desc;

1. 請查詢沒有領導的員工名和職位

select ename,job from emp where mgr is null;

1. 查詢有領導的員工名和職位

select ename,job from emp where mgr is not null;

1. 查詢全部員工名、職位以及領導名

select e1.ename,e1.job,e2.ename from emp e1,emp e2 where e1.mgr = e2.empno(+);

1. 查詢部門30中的全部員工信息

select * from emp where deptno = 30;

1. 列出全部辦事員(CLERK)的姓名,編號和部門編號(按部門編號升序排列)

select ename,empno,deptno from emp where job = 'CLERK' order by deptno;

1. 找出佣金高於薪金的員工

select * from emp where nvl(comm,0) > sal;

1. 找出佣金低於薪金的40%的員工信息

select * from emp where nvl(comm,0) < sal*0.4;