今天是学数据库的第一天，之前安装Oracle几经波折终于装成功(缺监听，加监听和替换tns)。学习如何建表，可视画界面直观简单，但还是学习用脚本语言写出来，建了员工表，岗位表，工资等级表，刚开始建错不懂怎么修改，是删掉整个文件，发现内容还在，后来学到直接用语句改错，和删除，插入。
不管编写几张表，脚本都可写在一个xx.sql
alter session set nls_date_format='yyyy-mm-dd hh:mi:ss';
insert into emp values(1001,'子容','CTO',0,'2020-11-10',2000,5000,1);
update emp set sal=20000 where empno=1001;
insert into emp values(1002,'小梅','测试',0,'2020-12-10',10000,5000,2);
insert into emp values(1003,'洁杏','前端',1005,'2020-10-10',10000,6000,3);
insert into emp values(1004,'杏群','后端',1005,'2020-10-10',11000,5000,4);
insert into emp values(1005,'港哥','后端',0,'2020-11-10',12000,6000,4);
insert into emp values(1006,'艳梅','后端',1005,'2020-10-10',11000,6000,4);
insert into emp values(1006,'家梅','美工',1005,'2020-9-10',11000,6000,5);
insert into emp values(1007,'丽兰','HR',1001,'2020-12-10',11000,6000,6);
insert into emp values(1008,'俊宇','工程师',0,'2020-12-10',12000,6000,7);
insert into emp values(1009,'小芳','程序员',1005,'2020-11-10',12000,6000,8);
insert into emp values(1010,'黄蓉','程序员',1001,'2020-8-10',11000,6000,8);
select * from emp;
drop table DEPT;
create table dept(
deptno number(4) primary key,
dname varchar2(20),
log varchar2(20)
)
insert into dept values(1,'CTO','东');
insert into dept values(2,'测试','西');
insert into dept values(3,'前端','南');
insert into dept values(4,'后端','北');
select * from dept;
create table sallv(
lv number(4) primary key,
min number(10),
max number(10)
)
insert into sallv values(1,2000,10000);
insert into sallv values(2,10000,11000);
insert into sallv values(3,11000,12000);
update sallv set min=12000 where lv=1;
update sallv set max=20000 where lv=1;
update sallv set min=11000 where lv=2;
update sallv set max=12000 where lv=2;
update sallv set min=10000 where lv=3;
update sallv set max=11000 where lv=3;
select * from sallv;
select dname,log from dept;
select ename,sal from emp;
select 12*3 from dual;
select ename as "姓名",sal*12+comm as "年 薪" from emp;
select '姓名:'||ename as "别致的列名" from emp;
select ename as "姓名",'年薪'||(sal*12+comm) as "年 薪" from emp;
select nvl(11,1000) from dual;
select * from emp;