數據庫如何正確的連接以及關閉（PHP）

我在網頁的頭部寫了<?php require_once('Connections/member.php'); ?>
這裡是member.php的代碼<?php

FileName="Connection_php_mysql.htm"

Type="MYSQL"

HTTP="true"

$hostname_member = "";
$database_member = "";
$username_member = "";
$password_member = ";
$member = mysql_connect($hostname_member, $username_member, $password_member) or trigger_error(mysql_error(),E_USER_ERROR);

?>這樣寫經常造成流量異常，怎麼改寫

最佳回答：

 $hostname_member = "";
$database_member = "";
$username_member = "";
$password_member = ";

 $member = mysql_connect($hostname_member, $username_member, $password_member) or trigger_error(mysql_error(),E_USER_ERROR); 

為什麼你把用戶名和密碼都置為空再去鏈接呢？？我實在看不懂。。