ORACLE和SQL SERVER和MYSQL很不同，没有数据库的概念，是个tablespace 表空间，每个用户有自己的表空间
建立 表空间的过程如下
CREATE TABLESPACE mytest
DATAFILE '/u01/app/oracle/oradata/xe/mytest01.dbf'
SIZE 100M
AUTOEXTEND ON NEXT 100M MAXSIZE UNLIMITED;
CREATE TEMPORARY TABLESPACE temp_mytest
TEMPFILE '/u01/app/oracle/oradata/xe/temp_mytest01.dbf'
SIZE 1024M
AUTOEXTEND ON NEXT 100M MAXSIZE UNLIMITED;
CREATE USER mytest IDENTIFIED BY password12 DEFAULT TABLESPACE mytest TEMPORARY TABLESPACE temp_mytest;
GRANT CONNECT, RESOURCE TO mytest;