CREATE USER white IDENTIFIED BY oracle123;
-- 實際創(chuàng)建的用戶名是 "WHITE"

CREATE USER "White" IDENTIFIED BY oracle123;
-- 創(chuàng)建的用戶名保持 "White" 的精確大小寫

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

-- 創(chuàng)建大小寫敏感的用戶名
CREATE USER "AdminUser" IDENTIFIED BY "Pass123!";

-- 必須先刪除原用戶（注意備份對象權(quán)限）
DROP USER "myuser";

-- 創(chuàng)建帶正確大小寫的新用戶
CREATE USER "MyUser" IDENTIFIED BY "newpassword";

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

-- 查看所有用戶名及其大小寫形式
SELECT username FROM dba_users 
WHERE REGEXP_LIKE(username, '[a-z]')  -- 查找包含小寫字母的用戶名
ORDER BY username;

-- 精確檢查特定用戶名
SELECT username FROM dba_users 
WHERE username IN ('WHITE', 'White', 'white');

SQL> SELECT username FROM dba_users 
  2  WHERE REGEXP_LIKE(username, '[a-z]')  -- 查找包含小寫字母的用戶名
  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";

-- 監(jiān)控大小寫敏感用戶的登錄情況
SELECT os_username, username, userhost, timestamp
FROM dba_audit_trail
WHERE username LIKE '%"%'  -- 查找?guī)б柕挠脩裘?
ORDER BY timestamp DESC;

# 正確方式（Python示例）
# 對于創(chuàng)建為 "AppUser" 的用戶
dsn = cx_Oracle.makedsn("host", 1521, service_name="ORCL")
conn = cx_Oracle.connect(user='"AppUser"', password='pwd', dsn=dsn)

-- 生成遷移腳本
SELECT 'CREATE USER "' || username || '" IDENTIFIED BY VALUES ''' || password || ''';'
FROM dba_users
WHERE username NOT LIKE '%"%'  -- 排除已帶引號的用戶
AND username != 'SYS';        -- 排除系統(tǒng)用戶

-- 生成授權(quán)腳本
SELECT 'GRANT ' || granted_role || ' TO "' || grantee || '";'
FROM dba_role_privs
WHERE grantee NOT LIKE '%"%';

-- SQL*Plus 中連接示例
CONNECT "MixedUser"/password