Fatal error: Uncaught mysqli_sql_exception: Access denied for user 'root'@'localhost' (using password: NO) in /www/xzlweb.top/xzl/php/0601/test/test_db4.php:7 Stack trace: #0 /www/xzlweb.top/xzl/php/0601/test/test_db4.php(7): mysqli_connect() #1 {main} thrown in /www/xzlweb.top/xzl/php/0601/test/test_db4.php on line 7