Oracle 用户名大小写控制的实现示例

CREATE USER white IDENTIFIED BY oracle123;
-- 实际创建的用户名是 "WHITE"

CREATE USER "White" IDENTIFIED BY oracle123;
-- 创建的用户名保持 "White" 的精确大小写

SQL> CREATE USER white IDENTIFIED BY oracle123;

User created.

SQL> CREATE USER "White" IDENTIFIED BY oracle123;

User created.

SQL> select username from dba_users where lower(username)='white';

USERNAME
--------------------------------------------------------------------------------
WHITE
White

-- 创建大小写敏感的用户名
CREATE USER "AdminUser" IDENTIFIED BY "Pass123!";

-- 必须先删除原用户（注意备份对象权限）
DROP USER "myuser";

-- 创建带正确大小写的新用户
CREATE USER "MyUser" IDENTIFIED BY "newpassword";

-- 重新授权（示例）
GRANT CONNECT, RESOURCE TO "MyUser";

-- 查看所有用户名及其大小写形式
SELECT username FROM dba_users 
WHERE REGEXP_LIKE(username, '[a-z]')  -- 查找包含小写字母的用户名
ORDER BY username;

-- 精确检查特定用户名
SELECT username FROM dba_users 
WHERE username IN ('WHITE', 'White', 'white');

SQL> SELECT username FROM dba_users 
  2  WHERE REGEXP_LIKE(username, '[a-z]')  -- 查找包含小写字母的用户名
  3  ORDER BY username;

USERNAME
--------------------------------------------------------------------------------
White
white

SQL> 
SQL> SELECT username FROM dba_users 
  2  WHERE username IN ('WHITE', 'White', 'white');

USERNAME
--------------------------------------------------------------------------------
White
white
WHITE

SQL> 

CREATE USER APP_ADMIN IDENTIFIED BY "xxxxxx";

-- 监控大小写敏感用户的登录情况
SELECT os_username, username, userhost, timestamp
FROM dba_audit_trail
WHERE username LIKE '%"%'  -- 查找带引号的用户名
ORDER BY timestamp DESC;

# 正确方式（Python示例）
# 对于创建为 "AppUser" 的用户
dsn = cx_Oracle.makedsn("host", 1521, service_name="ORCL")
conn = cx_Oracle.connect(user='"AppUser"', password='pwd', dsn=dsn)

-- 生成迁移脚本
SELECT 'CREATE USER "' || username || '" IDENTIFIED BY VALUES ''' || password || ''';'
FROM dba_users
WHERE username NOT LIKE '%"%'  -- 排除已带引号的用户
AND username != 'SYS';        -- 排除系统用户

-- 生成授权脚本
SELECT 'GRANT ' || granted_role || ' TO "' || grantee || '";'
FROM dba_role_privs
WHERE grantee NOT LIKE '%"%';

-- SQL*Plus 中连接示例
CONNECT "MixedUser"/password