不因俊俏难为友，正为风流始读书

插入多条记录：insert into student(stu_id,stu_name) select id,name from stu;添加字段alter table student add bith varchar2(10);创建序列create sequence seq_namestart with 1increment by 使用序列insert

创建表空间：create tablespace tablespace_namedatafile '存放dbf文件的路径'size 20Mautoextend on next 10M maxsize unlimited;创建用户分配表空间：create user user_nameidentified by  passworddefault tablespace ta

聚合函数：select max(stu_score),min(stu_id),avg(stu_score),sum(stu_score),count(stu_id) from student;转换为字符：select to_char(sysdate,'yyyy-mm-dd') from dual;转换为日期： select to_date('2017-08-20','y

序列：create sequence sequence_namestart  with 1increment by 1;序列使用:insert into table_name [column] values(sequence_name.nextval,值列表)登录用户：conn 用户名/密码@orcl解锁用户:alter  user user_name acco

1. 假设A公司的管理系统中有部门信息表(Dept)、员工信息表(Emp)、工资信息表(Sal)，表结构如下图所示：Dept部门号部门名称DnoDnameEmp员工号姓名性别年龄部门号EnoEnameEsexEageDnoSal员工号工资等级工

select * from salgrade;select * from emp;--显示员工的名字、工资及部门的名字select e.ename,e.sal,d.dname from emp e,dept d where e.deptno=d.deptno;--显示部门编号为10的部门的员工的名字、工资及部门的名称select e.ename,e.sa

select * from deptselect * from (select e.empno,e.ename,rownum r from (select empno,ename from emp order by empno) e where rownum>=20)where r<=30--无返回值的存储过程create or replace procedure proc_ins_dept