用sql developer创建新用户出现问题。。新手，第一次用oracle，求解

Question

在行 2 上开始执行命令时出错:
CREATE USER ##liupeng IDENTIFIED BY liupeng
DEFAULT TABLESPACE "USERS"
TEMPORARY TABLESPACE "TEMP"
命令出错, 行: 2 列: 13
错误报告:
SQL 错误: ORA-00911: 无效字符
00911. 00000 - "invalid character"
*Cause: identifiers may not start with any ASCII character other than
letters and numbers. $#_ are also allowed after the first
character. Identifiers enclosed by doublequotes may contain
any character other than a doublequote. Alternative quotes
(q'#...#') cannot use spaces, tabs, or carriage returns as
delimiters. For all other contexts, consult the SQL Language
Reference Manual.
*Action:

在行 7 上开始执行命令时出错:
GRANT "DBA" TO ##liupeng
错误报告:
SQL 错误: ORA-00911: 无效字符
00911. 00000 - "invalid character"
*Cause: identifiers may not start with any ASCII character other than
letters and numbers. $#_ are also allowed after the first
character. Identifiers enclosed by doublequotes may contain
any character other than a doublequote. Alternative quotes
(q'#...#') cannot use spaces, tabs, or carriage returns as
delimiters. For all other contexts, consult the SQL Language
Reference Manual.
*Action:

在行 12 上开始执行命令时出错:
ALTER USER ##liupeng QUOTA UNLIMITED ON SYSTEM
错误报告:
SQL 错误: ORA-00911: 无效字符
00911. 00000 - "invalid character"
*Cause: identifiers may not start with any ASCII character other than
letters and numbers. $#_ are also allowed after the first
character. Identifiers enclosed by doublequotes may contain
any character other than a doublequote. Alternative quotes
(q'#...#') cannot use spaces, tabs, or carriage returns as
delimiters. For all other contexts, consult the SQL Language
Reference Manual.

Answer 1

很明显报错是因为“USERS”双引号无法标识，正确语法如下：
create user scott identified by tigger
default tablespace USERS
temporary tablespace TEMP;