Oracle数据库基础（一）

先数据库引入：引入基本数据

prompt PL/SQL Developer import file
set feedback off
set define off
prompt Creating BONUS...
create table BONUS
(
  ename VARCHAR2(10),
  job   VARCHAR2(9),
  sal   NUMBER,
  comm  NUMBER
)
tablespace USERS
  pctfree 10
  initrans 1
  maxtrans 255;

prompt Creating DEPT...
create table DEPT
(
  deptno NUMBER(2) not null,
  dname  VARCHAR2(14),
  loc    VARCHAR2(13)
)
tablespace USERS
  pctfree 10
  initrans 1
  maxtrans 255
  storage
  (
    initial 64K
    next 1M
    minextents 1
    maxextents unlimited
  );
alter table DEPT
  add constraint PK_DEPT primary key (DEPTNO)
  using index 
  tablespace USERS
  pctfree 10
  initrans 2
  maxtrans 255
  storage
  (
    initial 64K
    next 1M
    minextents 1
    maxextents unlimited
  );

prompt Creating EMP...
create table EMP
(
  empno    NUMBER(4) not null,
  ename    VARCHAR2(10),
  job      VARCHAR2(9),
  mgr      NUMBER(4),
  hiredate DATE,
  sal      NUMBER(7,2),
  comm     NUMBER(7,2),
  deptno   NUMBER(2)
)
tablespace USERS
  pctfree 10
  initrans 1
  maxtrans 255
  storage
  (
    initial 64K
    next 1M
    minextents 1
    maxextents unlimited
  );
alter table EMP
  add constraint PK_EMP primary key (EMPNO)
  using index 
  tablespace USERS
  pctfree 10
  initrans 2
  maxtrans 255
  storage
  (
    initial 64K
    next 1M
    minextents 1
    maxextents unlimited
  );
alter table EMP
  add constraint FK_DEPTNO foreign key (DEPTNO)
  references DEPT (DEPTNO);

prompt Creating SALGRADE...
create table SALGRADE
(
  grade NUMBER,
  losal NUMBER,
  hisal NUMBER
)
tablespace USERS
  pctfree 10
  initrans 1
  maxtrans 255
  storage
  (
    initial 64K
    next 1M
    minextents 1
    maxextents unlimited
  );

prompt Disabling triggers for BONUS...
alter table BONUS disable all triggers;
prompt Disabling triggers for DEPT...
alter table DEPT disable all triggers;
prompt Disabling triggers for EMP...
alter table EMP disable all triggers;
prompt Disabling triggers for SALGRADE...
alter table SALGRADE disable all triggers;
prompt Disabling foreign key constraints for EMP...
alter table EMP disable constraint FK_DEPTNO;
prompt Loading BONUS...
prompt Table is empty
prompt Loading DEPT...
insert into DEPT (deptno, dname, loc)
values (10, 'ACCOUNTING', 'NEW YORK');
insert into DEPT (deptno, dname, loc)
values (20, 'RESEARCH', 'DALLAS');
insert into DEPT (deptno, dname, loc)
values (30, 'SALES', 'CHICAGO');
insert into DEPT (deptno, dname, loc)
values (40, 'OPERATIONS', 'BOSTON');
commit;
prompt 4 records loaded
prompt Loading EMP...
insert into EMP (empno, ename, job, mgr, hiredate, sal, comm, deptno)
values (7369, 'SMITH', 'CLERK', 7902, to_date('17-12-1980', 'dd-mm-yyyy'), 800, null, 20);
insert into EMP (empno, ename, job, mgr, hiredate, sal, comm, deptno)
values (7499, 'ALLEN', 'SALESMAN', 7698, to_date('20-02-1981', 'dd-mm-yyyy'), 1600, 300, 30);
insert into EMP (empno, ename, job, mgr, hiredate, sal, comm, deptno)
values (7521, 'WARD', 'SALESMAN', 7698, to_date('22-02-1981', 'dd-mm-yyyy'), 1250, 500, 30);
insert into EMP (empno, ename, job, mgr, hiredate, sal, comm, deptno)
values (7566, 'JONES', 'MANAGER', 7839, to_date('02-04-1981', 'dd-mm-yyyy'), 2975, null, 20);
insert into EMP (empno, ename, job, mgr, hiredate, sal, comm, deptno)
values (7654, 'MARTIN', 'SALESMAN', 7698, to_date('28-09-1981', 'dd-mm-yyyy'), 1250, 1400, 30);
insert into EMP (empno, ename, job, mgr, hiredate, sal, comm, deptno)
values (7698, 'BLAKE', 'MANAGER', 7839, to_date('01-05-1981', 'dd-mm-yyyy'), 2850, null, 30);
insert into EMP (empno, ename, job, mgr, hiredate, sal, comm, deptno)
values (7782, 'CLARK', 'MANAGER', 7839, to_date('09-06-1981', 'dd-mm-yyyy'), 2450, null, 10);
insert into EMP (empno, ename, job, mgr, hiredate, sal, comm, deptno)
values (7788, 'SCOTT', 'ANALYST', 7566, to_date('19-04-1987', 'dd-mm-yyyy'), 3000, null, 20);
insert into EMP (empno, ename, job, mgr, hiredate, sal, comm, deptno)
values (7839, 'KING', 'PRESIDENT', null, to_date('17-11-1981', 'dd-mm-yyyy'), 5000, null, 10);
insert into EMP (empno, ename, job, mgr, hiredate, sal, comm, deptno)
values (7844, 'TURNER', 'SALESMAN', 7698, to_date('08-09-1981', 'dd-mm-yyyy'), 1500, 0, 30);
insert into EMP (empno, ename, job, mgr, hiredate, sal, comm, deptno)
values (7876, 'ADAMS', 'CLERK', 7788, to_date('23-05-1987', 'dd-mm-yyyy'), 1100, null, 20);
insert into EMP (empno, ename, job, mgr, hiredate, sal, comm, deptno)
values (7900, 'JAMES', 'CLERK', 7698, to_date('03-12-1981', 'dd-mm-yyyy'), 950, null, 30);
insert into EMP (empno, ename, job, mgr, hiredate, sal, comm, deptno)
values (7902, 'FORD', 'ANALYST', 7566, to_date('03-12-1981', 'dd-mm-yyyy'), 3000, null, 20);
insert into EMP (empno, ename, job, mgr, hiredate, sal, comm, deptno)
values (7934, 'MILLER', 'CLERK', 7782, to_date('23-01-1982', 'dd-mm-yyyy'), 1300, null, 10);
commit;
prompt 14 records loaded
prompt Loading SALGRADE...
insert into SALGRADE (grade, losal, hisal)
values (1, 700, 1200);
insert into SALGRADE (grade, losal, hisal)
values (2, 1201, 1400);
insert into SALGRADE (grade, losal, hisal)
values (3, 1401, 2000);
insert into SALGRADE (grade, losal, hisal)
values (4, 2001, 3000);
insert into SALGRADE (grade, losal, hisal)
values (5, 3001, 9999);
commit;
prompt 5 records loaded
prompt Enabling foreign key constraints for EMP...
alter table EMP enable constraint FK_DEPTNO;
prompt Enabling triggers for BONUS...
alter table BONUS enable all triggers;
prompt Enabling triggers for DEPT...
alter table DEPT enable all triggers;
prompt Enabling triggers for EMP...
alter table EMP enable all triggers;
prompt Enabling triggers for SALGRADE...
alter table SALGRADE enable all triggers;
set feedback on
set define on
prompt Done.

 

-------------------------------------------
--选择所有列
-------------------------------------------

1、*表示所有列（选择）：

select * from emp;

2.指定所有列的具体的名称：

select empno,ename,job,mgr,hiredate,sal,comm,deptno from emp; --效率高

-------------------------------------------
--选择指定列
-------------------------------------------

3.查询指定列(投影)
 

select empno,ename,job from emp;

-------------------------------------------
--使用算数运算符
--      null 表示值不存在，或值无效，不同于0，也不同于''
--                   null值与任意值计算都为null
--
--       nvl(参数一，参数二)：当参数一为null时，取参数二的值，否则默认取参数一
-------------------------------------------

--1.统计所有雇员的年薪
select empno,ename,sal,sal*12 from emp;

--2.统计所有雇员的年薪（假设试用期6个月，试用工资为转正工资的80%，包括奖金）
select empno, ename, sal, comm, (sal * 6) + (sal * 6 * 1.2) + (comm) from emp; --comm有问题，当值为null时，获取的结果也为null
select empno,
       ename,
       sal,
       comm,
       ((sal * 6) + (sal * 6 * 1.2) + (nvl(comm, 0))) --使用nvl()函数处理计算过程中的null值
  from emp;

-------------------------------------------
--取别名
--    使用列别名的方法：
--           1.列名 别名
--           2.列名 as 别名

--    以下三种情况列别名两侧需要添加双引号：
--           1.列别名中包含有空格
--           2.列别名中要求区分大小写
--           3.列别名中包含有特殊字符
-------------------------------------------

--1.统计所有雇员的年薪,且年薪使用别名yearSalary表示（假设试用期6个月，试用工资为转正工资的80%，包-括奖金）
select empno,
       ename,
       sal,
       comm,
       ((sal * 6) + (sal * 6 * 1.2) + (nvl(comm, 0))) yearSalary
  from emp;

--列别名使用两种方法
select empno 编号,   --列名 别名
       ename as 姓名 --列名 as 别名
from emp;

--注意
select empno,ename,sal * 12 "year salary" from emp;--列别名中包含有空格
select empno,ename,sal * 12 "yearSalary" from emp; --列别名中要求区分大小写
select empno,ename,sal * 12 "year'salary" from emp;--列别名中包含有特殊字符

-----------------------------------
--连接操作符
--原义字符串：使用单引号''括起来，并出现在每行数据中
-----------------------------------

--1.查询雇员的姓名与职位，并以“XXX的职位是XXX”格式显示
select ename,job,(ename || '的职位是' || job) from emp;

-----------------------------------
--消除重复行 : distinct
-----------------------------------

--1.查询所有有员工的部门编号信息
select distinct deptno from emp;--单列去重

--2.查询所有有员工的部门编号，以及岗位信息
select distinct deptno,job from emp;--多列重复

-----------------------------------
--descripbe名称，查看表结构（SQL*PLUS命令）
-----------------------------------

--1.查看emp表的结构
desc emp;--仅允许在命令窗口执行