关于Oracle数据库中的employee实例表
Oracle数据库安装的时候会自带一个练习用数据库（其中包含employee表，后来版本中此表改名为emp）；

首先在安装过程中应该有个选项“是否安装实例表”（完全安装模式下默认是选择的），需要选择才有此表；

此表归属于scott账户，scott用户默认口令为tiger
如果发现scott账户已过期（Oracle 10g中经常发生），或口令不正确，可以通过以下方法进行设置

--账户解锁
alter user scott account unlock;
--重设scott账户口令为tiger
alter user scott identified by tiger;

附:实例表建表语句（适用于Oracle）

----------------------demobld.sql begin-----------------------
--
-- Copyright (c) Oracle Corporation 1988, 2000. All Rights Reserved.
--
-- NAME
-- demobld.sql
--
-- DESCRIPTION
-- This script. creates the SQL*Plus demonstration tables in the
-- current schema. It should be STARTed by each user wishing to
-- access the tables. To remove the tables use the demodrop.sql
-- script.
--
-- USAGE
-- From within SQL*Plus, enter:
-- START demobld.sql

SET TERMOUT ON
PROMPT Building demonstration tables. Please wait.
SET TERMOUT OFF

DROP TABLE EMP;
DROP TABLE DEPT;
DROP TABLE BONUS;
DROP TABLE SALGRADE;
DROP TABLE DUMMY;

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));

INSERT INTO EMP VALUES
(7369, 'SMITH', 'CLERK', 7902,
TO_DATE('17-DEC-1980', 'DD-MON-YYYY'), 800, NULL, 20);
INSERT INTO EMP VALUES
(7499, 'ALLEN', 'SALESMAN', 7698,
TO_DATE('20-FEB-1981', 'DD-MON-YYYY'), 1600, 300, 30);
INSERT INTO EMP VALUES
(7521, 'WARD', 'SALESMAN', 7698,
TO_DATE('22-FEB-1981', 'DD-MON-YYYY'), 1250, 500, 30);
INSERT INTO EMP VALUES
(7566, 'JONES', 'MANAGER', 7839,
TO_DATE('2-APR-1981', 'DD-MON-YYYY'), 2975, NULL, 20);
INSERT INTO EMP VALUES
(7654, 'MARTIN', 'SALESMAN', 7698,
TO_DATE('28-SEP-1981', 'DD-MON-YYYY'), 1250, 1400, 30);
INSERT INTO EMP VALUES
(7698, 'BLAKE', 'MANAGER', 7839,
TO_DATE('1-MAY-1981', 'DD-MON-YYYY'), 2850, NULL, 30);
INSERT INTO EMP VALUES
(7782, 'CLARK', 'MANAGER', 7839,
TO_DATE('9-JUN-1981', 'DD-MON-YYYY'), 2450, NULL, 10);
INSERT INTO EMP VALUES
(7788, 'SCOTT', 'ANALYST', 7566,
TO_DATE('09-DEC-1982', 'DD-MON-YYYY'), 3000, NULL, 20);
INSERT INTO EMP VALUES
(7839, 'KING', 'PRESIDENT', NULL,
TO_DATE('17-NOV-1981', 'DD-MON-YYYY'), 5000, NULL, 10);
INSERT INTO EMP VALUES
(7844, 'TURNER', 'SALESMAN', 7698,
TO_DATE('8-SEP-1981', 'DD-MON-YYYY'), 1500, 0, 30);
INSERT INTO EMP VALUES
(7876, 'ADAMS', 'CLERK', 7788,
TO_DATE('12-JAN-1983', 'DD-MON-YYYY'), 1100, NULL, 20);
INSERT INTO EMP VALUES
(7900, 'JAMES', 'CLERK', 7698,
TO_DATE('3-DEC-1981', 'DD-MON-YYYY'), 950, NULL, 30);
INSERT INTO EMP VALUES
(7902, 'FORD', 'ANALYST', 7566,
TO_DATE('3-DEC-1981', 'DD-MON-YYYY'), 3000, NULL, 20);
INSERT INTO EMP VALUES
(7934, 'MILLER', 'CLERK', 7782,
TO_DATE('23-JAN-1982', 'DD-MON-YYYY'), 1300, NULL, 10);

CREATE TABLE DEPT
(DEPTNO NUMBER(2),
DNAME VARCHAR2(14),
LOC VARCHAR2(13) );

INSERT INTO DEPT VALUES (10, 'ACCOUNTING', 'NEW YORK');
INSERT INTO DEPT VALUES (20, 'RESEARCH', 'DALLAS');
INSERT INTO DEPT VALUES (30, 'SALES', 'CHICAGO');
INSERT INTO DEPT VALUES (40, 'OPERATIONS', 'BOSTON');

CREATE TABLE BONUS
(ENAME VARCHAR2(10),
JOB VARCHAR2(9),
SAL NUMBER,
COMM NUMBER);

CREATE TABLE SALGRADE
(GRADE NUMBER,
LOSAL NUMBER,
HISAL NUMBER);

INSERT INTO SALGRADE VALUES (1, 700, 1200);
INSERT INTO SALGRADE VALUES (2, 1201, 1400);
INSERT INTO SALGRADE VALUES (3, 1401, 2000);
INSERT INTO SALGRADE VALUES (4, 2001, 3000);
INSERT INTO SALGRADE VALUES (5, 3001, 9999);

CREATE TABLE DUMMY
(DUMMY NUMBER);

INSERT INTO DUMMY VALUES (0);

COMMIT;

SET TERMOUT ON
PROMPT Demonstration table build is complete.

EXIT
-------------------demobld.sql end-----------------------

实例建表语句（适用于MySQL）

DROP TABLE employee;
DROP TABLE dept;
DROP TABLE bonus;
DROP TABLE salgrade;
DROP TABLE dummy;

CREATE TABLE employee
(
  employeeno DECIMAL(4) NOT N