安装了12c版本，发现没有scott用户和11g自带的emp，dept等等的表。于是尝试解锁用户，发现用户不存在。

sql> alter user scott account unlock;
alter user scott account unlock
           *
ERROR at line 1:
ORA-01918: user 'SCOTT' does not exist

手动创建用户，出错，和11g不太一样：

sql> create user scott identified by oracle;
create user scott identified by oracle
            *
ERROR at line 1:
ORA-65096: invalid common user or role name

原因和pdb，cdb有关。Oracle 12C引入了CDB与PDB的新特性，在ORACLE 12C数据库引入的多租用户环境（Multitenant Environment）中，允许一个数据库容器（CDB）承载多个可插拔数据库（PDB）。CDB全称为Container Database，中文翻译为数据库容器，PDB全称为Pluggable Database，即可插拔数据库。在ORACLE 12C之前，实例与数据库是一对一或多对一关系（RAC）：即一个实例只能与一个数据库相关联，数据库可以被多个实例所加载。而实例与数据库不可能是一对多的关系。当进入ORACLE 12C后，实例与数据库可以是一对多的关系。下面是官方文档关于CDB与PDB的关系图。

查看错误ORA--65096：（oracle自带错误查找工具：!oerrora65096[错误代码]）

特别注意：

该工具位于$ORACLE_HOME/bin/oerr
该工具所调用的错误信息列表文件为 $ORACLE_HOME/rdbms/mesg/oraus.msg
该工具不可用于windows上，经测试，9i,10g,11g,12c都有此工具。

sql>  !oerr ora 65096
65096,00000,"invalid common user or role name"
// *Cause:  An attempt was made to create a common user or role with a name
//          that wass not valid for common users or roles.  In addition to 
//          the usual rules for user and role names,common user and role 
//          names must start with C## or c## and consist only of ASCII 
//          characters.
// *Action: Specify a valid common user or role name.
//

在CDB中用户得以C##开头。

创建scott用户和表的sql文件在oracle的安装目录下：

D:\app\oracle\product\12.1.0\dbhome_1\RDBMS\ADMIN\utlsampl.sql

复制一个副本到当前目录，重命名为create.sql

修改create.sql:

主要是将scott用户相关的语句改为c##scott，删除最后的EXIT，修改完的scott.sql如下：

create.sql:

SET TERMOUT OFF
SET ECHO OFF
 
DROP USER C##SCOTT CASCADE;
 
create user c##scott identified by tiger;
grant connect,resource,unlimited tablespace to c##scott container=all;
alter user c##scott default tablespace users;
alter user c##scott temporary tablespace temp;
 
CONNECT C##SCOTT/tiger
 
CREATE TABLE DEPT
       (DEPTNO NUMBER(2) CONSTRAINT PK_DEPT PRIMARY KEY,DNAME VARCHAR2(14),LOC VARCHAR2(13) ) ;
CREATE TABLE EMP
       (EMPNO NUMBER(4) CONSTRAINT PK_EMP PRIMARY KEY,ENAME VARCHAR2(10),JOB VARCHAR2(9),MGR NUMBER(4),HIREDATE DATE,SAL NUMBER(7,2),COMM NUMBER(7,DEPTNO NUMBER(2) CONSTRAINT FK_DEPTNO REFERENCES DEPT);
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');
INSERT INTO EMP VALUES
(7369,'SMITH','CLERK',7902,to_date('17-12-1980','dd-mm-yyyy'),800,NULL,20);
INSERT INTO EMP VALUES
(7499,'ALLEN','SALESMAN',7698,to_date('20-2-1981',1600,300,30);
INSERT INTO EMP VALUES
(7521,'WARD',to_date('22-2-1981',1250,500,30);
INSERT INTO EMP VALUES
(7566,'JONES','MANAGER',7839,to_date('2-4-1981',2975,20);
INSERT INTO EMP VALUES
(7654,'MARTIN',to_date('28-9-1981',1400,30);
INSERT INTO EMP VALUES
(7698,'BLAKE',to_date('1-5-1981',2850,30);
INSERT INTO EMP VALUES
(7782,'CLARK',to_date('9-6-1981',2450,10);
INSERT INTO EMP VALUES
(7788,'SCOTT','ANALYST',7566,to_date('13-JUL-87','dd-mm-rr')-85,3000,20);
INSERT INTO EMP VALUES
(7839,'KING','PRESIDENT',to_date('17-11-1981',5000,10);
INSERT INTO EMP VALUES
(7844,'TURNER',to_date('8-9-1981',1500,30);
INSERT INTO EMP VALUES
(7876,'ADAMS',7788,'dd-mm-rr')-51,1100,20);
INSERT INTO EMP VALUES
(7900,'JAMES',to_date('3-12-1981',950,30);
INSERT INTO EMP VALUES
(7902,'FORD',20);
INSERT INTO EMP VALUES
(7934,'MILLER',7782,to_date('23-1-1982',1300,10);
CREATE TABLE BONUS
    (
    ENAME VARCHAR2(10),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);
COMMIT;

测试：

sqlplus / as sysdba
sql> @d:\create.sql;
sql> conn c##scott/tiger

sql> select table_name from user_tables;
 
sql> select * from SALGRADE;

scott用户和表创建完成。