在PHP MySQL查询循环 [英] mysql query loop in php

问题描述

当我运行此脚本，Apache使用所有可用内存和服务器无响应：

When I run this script, apache uses all available memory and the server becomes unresponsive:

$db = new mysql();
$result = $db->query($sql);
while($row = $db->query($sql)) ...

为什么PHP限制不限制Apache进程？ PHP正在按 mod_php的与Apache ITK。

Why does PHP limit does not limit apache process? PHP is working as mod_php with apache itk.

我有PHP极限的php.ini 设置，我看到在此限制的phpinfo（）。我没有设置PHP脚本的任何限制。

I have PHP limit set in php.ini and I see this limit in phpinfo(). I do not have set any limit in PHP script.

推荐答案

正如你已经知道，在而（$行= $ DB-＆GT;查询（$的SQL））导致一个无限循环;它只是反复运行查询，直到服务器死亡或杀死的过程。你需要做的而（$行= $ result-＆GT;取（））或而（$行= $ result-＆GT; FETCH_ASSOC（ ...））。

As you already know, the while($row = $db->query($sql)) causes an infinite loop; it just runs the query over and over until the server dies or kills the process. You need to do while($row = $result->fetch()) or while($row = $result->fetch_assoc(...)).

另外，请<一href=\"http://stackoverflow.com/questions/12859942/why-shouldnt-i-use-mysql-functions-in-php?rq=1\">don't使用的mysql _ * ;在的mysql _ * 的功能是过时的，的德precated 和不安全。使用 的MySQLi 或 PDO 来代替。

Also, please don't use mysql_*; the mysql_* functions are outdated, deprecated, and insecure. Use MySQLi or PDO instead.

编辑：我起先不明白你的问题。这里有一个问题：在mod_php，并且运行Apache，这意味着它通过Apache进程请求的内存。因此，通过 $ DB-GT及所需的内存;查询（）被Apache，不是一个单独的mod_php的过程中使用。没有与mysql_ *函数一些已知的记忆问题。例如，如所描述<一href=\"http://stackoverflow.com/questions/8409171/memory-leak-in-php-when-fetching-large-dataset-from-mysql\">here, 的mysql_query（）所有缓存从查询数据。 mod_php的是，很显然，没有跟踪它，但是，因为你从来没有真正赋予这些数据PHP变量。所以，Apache的内存占用量不断增加，但mod_php，并且没有意识到这一点，所以在php.ini内存限制从不踢。

I didn't understand your question at first. Here's the problem: mod_php runs within Apache, meaning it requests memory through the Apache process. So, the memory required by $db->query() is used by Apache, not a separate mod_php process. There are some known memory problems with the mysql_* functions. For example, as described here, mysql_query() buffers all of the data from the query. mod_php is, apparently, not tracking it, however, because you are never actually assigning that data to PHP variables. So, Apache's memory footprint keeps growing, but mod_php doesn't realize it, so the php.ini memory limit never kicks in.

正如我前面所说，你应该避免mysql_ *函数和MySQL类，并使用库MySQLi或PDO。这种错误行为是一个很好的理由。祝你好运！

As I said above, you should avoid the mysql_* functions and MySQL class, and use either MySQLi or PDO. This kind of buggy behavior is one good reason for that. Good luck!

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