Oracle限制某个帐号只能在特定机器上访问数据库
CREATE OR REPLACE TRIGGER logon_ip_control
AFTER logon ON user_test.schema
BEGIN
IF USER IN ('user_test') THEN
IF sys_context('USERENV', 'IP_ADDRESS') NOT IN
('192.168.1.10', '192.168.1.10') THEN
raise_application_error(-20001,
'You are not allowed to connect to the database');
END IF;
END IF;
END;