Oracle数据库中的employee实例表的建表操作（用于SQL练习）

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;  

如果想通过这个例子练手，下面是对应的建表语句，读者可以自行创建数据库进行练习（特别是Mysql用户）。对应的练习题，网上有很多，读者可自行搜索，这里就不一一列举。

附:实例表建表语句（适用于Oracle）

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  

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 NULL,    ename VARCHAR(10),    job VARCHAR(9),    mgr DECIMAL(4),    hiredate DATE,    sal DECIMAL(7, 2),    comm DECIMAL(7, 2),    deptno DECIMAL(2)  );  INSERT INTO employee VALUES  (7369, 'SMITH', 'CLERK', 7902, '1980-12-17', 800, NULL, 20);  INSERT INTO employee VALUES  (7499, 'ALLEN', 'SALESMAN', 7698,'1981-2-20', 1600, 300, 30);  INSERT INTO employee VALUES  (7521, 'WARD', 'SALESMAN', 7698, '1981-2-22', 1250, 500, 30);  INSERT INTO employee VALUES  (7566, 'JONES', 'MANAGER', 7839, '1981-4-2', 2975, NULL, 20);  INSERT INTO employee VALUES  (7654, 'MARTIN', 'SALESMAN', 7698, '1981-9-28', 1250, 1400, 30);  INSERT INTO employee VALUES  (7698, 'BLAKE', 'MANAGER', 7839, '1981-5-1', 2850, NULL, 30);  INSERT INTO employee VALUES  (7782, 'CLARK', 'MANAGER', 7839, '1981-7-9', 2450, NULL, 10);  INSERT INTO employee VALUES  (7788, 'SCOTT', 'ANALYST', 7566, '1982-12-9', 3000, NULL, 20);  INSERT INTO employee VALUES  (7839, 'KING', 'PRESIDENT', NULL, '1981-11-17', 5000, NULL, 10);  INSERT INTO employee VALUES  (7844, 'TURNER', 'SALESMAN', 7698, '1981-9-8', 1500, 0, 30);  INSERT INTO employee VALUES  (7876, 'ADAMS', 'CLERK', 7788, '1983-1-12', 1100, NULL, 20);  INSERT INTO employee VALUES  (7900, 'JAMES', 'CLERK', 7698, '1981-12-3', 950, NULL, 30);  INSERT INTO employee VALUES  (7902, 'FORD', 'ANALYST', 7566, '1981-12-3', 3000, NULL, 20);  INSERT INTO employee VALUES  (7934, 'MILLER', 'CLERK', 7782, '1982-1-23', 1300, NULL, 10);  CREATE TABLE dept  (deptno DECIMAL(2),  dname VARCHAR(14),  loc VARCHAR(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 VARCHAR(10),  job VARCHAR(9),  sal DECIMAL,  comm DECIMAL);  CREATE TABLE salgrade  (grade DECIMAL,  losal DECIMAL,  hisal DECIMAL);  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 DECIMAL);  INSERT INTO dummy VALUES (0);