ORACLE 10 学习笔记命令 第一课。(付首昕)

ORACLE 10 学习笔记命令第一课。
1.
sqlplus /nolog
connect /as sysdba
alter user scott account unlock;
alter user scott identified by manager;
2.
grant  select on dept to nmerp;
revoke select on dept to nmerp;
select * from scott.dept
create table abc(a varchar2(10),b char(10));
alter  table abc add c number;
3.
select length('abcdef') from dual;
select trim( 'abc' )    from dual;
select substr('abcdefg',2,3) from dual;
4.
sysdate/current_date/next_day
max/min/sum/count/avg
user/decode
5.
select a.dname,b.ename,b.sal,b.comm,b.job
from dept a right join emp b
on a.deptno=b.deptno and a.deptno=10;
6.
select ename,to_char(hiredate,'YYYY-MM-DD') from emp;
7.
select max(sal),min(sal) from emp;
select avg(sal),sum(sal) from emp;
select variance(sal),stddev(sal) from emp; (方差和标准差)
select deptno,avg(sal),max(sal) from emp group by deptno;
select deptno,job,avg(sal),max(sal) from emp group by deptno,job;
select deptno,avg(sal),max(sal) from emp group by deptno having avg(sal)<2000;
8.
select dept.dname, emp.ename from dept,emp where dept.dname='sales';
select dept.dname, emp.ename from dept,emp where dept.deptno=emp.deptno;
select d.dname, e.ename from dept d , emp e where d.deptno=e.deptno;
select e.ename, e.sal, d.dname from emp e, dept d  where e.deptno=d.deptno;
9.
select a.ename, a.sal, b.grade from emp a, salgrade b
where a.sal between b.losal and b.hisal;
10.
select manager.ename from emp manager, emp worker where manager.empno=worker.mgr
and worker.ename='BLAKE';