error_reporting(0);

$old_pre = 'tdr_'; // 原表前缀

$new_pre = 'db_'; // 新表前缀

// 配置连接

$db = new mysqli('127.0.0.1', 'db_user', 'db_pass', 'db_name');

if ($db->connect_error) die('Connect Error (' . $db->connect_errno . ') ' . $db->connect_error);

$query = $db->query('SHOW TABLES;');

$list = $query->fetch_all();

echo 'table : ', count($list),'<hr>';

$len = strlen($old_pre);

foreach ($list as $val) {

    $new_name = $new_pre.substr($val[0], $len, strlen($val[0])-$len);

    echo "ALTER TABLE {$val[0]} RENAME {$new_name};<br />";

    $db->query("ALTER TABLE {$val[0]} RENAME {$new_name};");

}

echo '<hr>success.';

$db->close();