Oracle Create User & Grant user

建立使用者帳號
CREATE USER usernmae IDENTIFIED BY password ; ＃username 加雙引號;登入認大小寫亦需加雙引號
GRANT CREATE SESSION TO username;

授予權限
Grant select, insert, update, delete ON tabename TO username;

收回權限
REVOKE select ON tabename FROM username;

更改使用者帳號
UPDATE USER$ SET NAME='new_username' WHERE NAME='old_username';
ALTER SYSTEM CHECKPOINT;
ALTER SYSTEM FLUSH SHARED_POOL;
ALTER USER username IDENTIFIED BY newpassword;