相关疑难解决方法(0)

如何使用Oracle 11g和SQL Developer创建一个小而简单的数据库？我看到太多错误,我找不到任何方法来创建一个简单的数据库.例如

create database company; 

导致以下错误:

Error starting at line 1 in command:
create database company
Error at Command Line:1 Column:0
Error report:
SQL Error: ORA-01501: CREATE DATABASE failed
ORA-01100: database already mounted
01501. 00000 -  "CREATE DATABASE failed"
*Cause:    An error occurred during create database
*Action:   See accompanying errors.

编辑 - 这与我熟悉的MySQL和MS-SQL完全不同.不像我期望的那样直观.