-- 查询所有用户
 SELECT USERNAME FROM ALL_USERS;

 -- 查询所有表空间
 SELECT TABLESPACE_NAME FROM USER_TABLESPACES;

 -- 创建用户 和 密码
 CREATE USER [用户名] IDENTIFIED BY [密码] ;

 -- 删除用户
 DROP USER [用户名] CASCADE;

 -- 创建表空间
 CREATE TABLESPACE [表空间名] DATAFILE ['x:\xxx\xxx\xxx.DBF'] SIZE 100M AUTOEXTEND ON NEXT 32M MAXSIZE 2048M;

 -- 删除表空间
 DROP TABLESPACE [表空间名] INCLUDING CONTENTS AND DATAFILES CASCADE CONSTRAINTS;

 -- 给用户授权
 GRANT DBA TO [用户名];

 -- 将空间分配给用户
 ALTER USER [用户名] DEFAULT TABLESPACE [表空间名] ;