我需要使用mysql_close（连接）吗？

问题描述：

I have the following code in db.php to connect to my DB.

<?php
$DB_HOST        = "localhost";
$DB_NAME        = "db";
$DB_USER        = "user";
$DB_PASSWORD        = "pass";

$con = mysql_connect($DB_HOST, $DB_USER, $DB_PASSWORD);

if (!$con)
{
  die('Could not connect: ' . mysql_error());
}

mysql_select_db($DB_NAME , $con);
?>

In my other script I include it using:

include("db.php");

In some cases I receive the ff error:

[10-Mar-2012 10:47:20] PHP Warning: mysql_connect() [function.mysql-connect]: User db_user already has more than 'max_user_connections' active connections in /home/user/public_html/sc/db.php on line 8

Now, I am wondering if I need to close the connection like:

<?php
include("db.php");

//other stuff here

mysql_close($con);
?>

BTW, I have a value of 100 max_connections in my MySQL config.

I also research about persistent connection and I believe my code above is not a persistent connection.

我在db.php中有以下代码连接到我的数据库。 p> ＆lt;？php $ DB_HOST =“localhost”; $ DB_NAME =“db”; $ DB_USER =“user”; $ DB_PASSWORD =“pass”; $ con = mysql_connect（$ DB_HOST，$ DB_USER，$ DB_PASSWORD）; if（！$ con） { die（'无法连接：'。mysql_error（））; } mysql_select_db（ $ DB_NAME，$ con）; ？＆gt; code> pre>

在我的其他脚本中，我使用以下方法包含它： p>


  include（“db.php”）; 
  code>  pre> 
 
 在某些情况下，我收到ff错误： p> 
 
 
 [10  -Mar-2012 10:47:20] PHP警告：mysql_connect（）[function.mysql-connect]：用户db_user已经在/home/user/public_html/sc/db.php上有超过'max_user_connections'的活动连接 8  p> 
 
 
现在，我想知道是否需要关闭连接，如： p> 
 
 
 ＆lt;？php 
include（“db。  php“）; 
 
 //这里的其他东西
 
mysql_close（$ con）; 
？＆gt; 
  code>  pre> 
 
  BTW，我有一个值 1 我的MySQL配置中的00 max_connections。 p> 
 
 
我还研究了持久连接，我相信上面的代码不是持久连接。 p> 
  div>

答

No, this won't help you if you close it at the end of the script. mysql_close() is just useful in case you want to free up resources before you end your script, because your connection is closed as soon as execution of the script ends

答

If you don't close your connections, they will stay open and take up precious resources on the server. I guess there's there the security point too, you don't want to risk someone getting a hold of the connection.
I prefer to put my database in a class and use __construct to create the connection, and __destruct to close the connection. If your unfamiliar with classes. The __construct and __destruct gets called automatically when you create and destroy a class.

Edit:
There was originally meant to be an example. But I have a basic but working mysql class here https://stackoverflow.com/a/9651249/1246494.

It shows the usage of mysql_close and how I was trying to relate it to the class destructor. The point was, any network connection should be closed, whether your database is on a remote server, or localhost.

我需要使用mysql_close（连接）吗？

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