blocks|key|347277|text|听起来你只需要install+MySQLi。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|347278|如果你认为你已经这样做了，但仍然有问题，请张贴你的操作系统和任何其他可能有助于进一步诊断的东西。|347279|entityMap|0|LINK|mutability|MUTABLE|url|https://php.net/manual/en/mysqli.installation.php^0|7|E|0|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@$A|O|B|P|1|Q]]|C|$]]|$1|D|3|E|5|6|7|R|8|@]|9|@]|C|$]]|$1|F|3|-4|5|6|7|S|8|@]|9|@]|C|$]]]|G|$H|$5|I|J|K|C|$L|M]]]]

Sounds like you just need to <a href="https://php.net/manual/en/mysqli.installation.php" rel="noreferrer">install MySQLi</a>.

If you think you've done that and still have a problem, please post your operating system and anything else that might help diagnose it further.

blocks|key|3335646|text|您可以通过执行以下代码来检查mysqli库是否存在：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3335647|if+(!function_exists('mysqli_init')+&&+!extension_loaded('mysqli'))+{
++++echo+'We+don\'t+have+mysqli!!!';
}+else+{
++++echo+'Phew+we+have+it!';
}|code-block|syntax|javascript|3335648|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You can check if the mysqli libraries are present by executing this code:

<pre><code>if (!function_exists('mysqli_init') &amp;&amp; !extension_loaded('mysqli')) {
 echo 'We don\'t have mysqli!!!';
} else {
 echo 'Phew we have it!';
}
</code></pre>

blocks|key|3335694|text|如果您使用的是Ubuntu，请运行：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3335695|+sudo+apt-get+install+php-mysqlnd|code-block|syntax|javascript|3335696|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikipedia.org/wiki/Ubuntu_%2528operating_system%2529^0|7|6|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

If you are on <a href="http://en.wikipedia.org/wiki/Ubuntu_%28operating_system%29" rel="nofollow noreferrer">Ubuntu</a>, run:
<pre><code> sudo apt-get install php-mysqlnd
</code></pre>

blocks|key|3335721|text|如果你调用"new+mysqli(..)“在命名空间的类中，您可能会看到类似的错误Fatal+error:+Class+'foo\bar\mysqli'+not+found+in。解决此问题的方法是使用前面的反斜杠将其显式设置为根名称空间，如下所示：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3335722|<?php+
$mysqli+=+new+\MySQLi($db_server,+$db_user,+$db_pass,+$db_name);|code-block|syntax|javascript|3335723|entityMap^0|15|1C|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

If you're calling "new mysqli(..)" from within a class that is namespaced, you might see a similar error <code>Fatal error: Class 'foo\bar\mysqli' not found in</code>. The way to fix this is to explicitly set it to the root namespace with a preceding backslash like so:

<pre><code>&lt;?php 
$mysqli = new \MySQLi($db_server, $db_user, $db_pass, $db_name);
</code></pre>

blocks|key|3122764|text|除了取消注释php.ini中的php_mysqli.dll扩展之外，还要取消注释php.ini中的extension_dir指令并指定您的位置：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3122765|extension_dir+=+"C:\software\php\dist\ext"|code-block|syntax|javascript|3122766|这让它对我来说很有效。|3122767|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

In addition to uncommenting the php_mysqli.dll extension in php.ini, also uncomment the extension_dir directive in php.ini and specify your location: 

<pre><code>extension_dir = "C:\software\php\dist\ext"
</code></pre>

This made it work for me.

blocks|key|3122807|text|我的OS是Ubuntu。我通过使用以下命令解决了这个问题：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3122808|sudo+apt-get+install+php5-mysql|code-block|syntax|javascript|3122809|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikipedia.org/wiki/Operating_system|1|http://en.wikipedia.org/wiki/Ubuntu_%2528operating_system%2529^0|2|2|0|5|6|1|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]|$A|W|B|X|1|Y]]|C|$]]|$1|D|3|E|5|F|7|Z|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|10|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]|Q|$5|L|M|N|C|$O|R]]]]

My <a href="http://en.wikipedia.org/wiki/Operating_system" rel="nofollow">OS</a> is <a href="http://en.wikipedia.org/wiki/Ubuntu_%28operating_system%29" rel="nofollow">Ubuntu</a>. I solved this problem by using:

<pre><code>sudo apt-get install php5-mysql
</code></pre>

blocks|key|350049|text|如何在php.ini中启用mysqli|type|unstyled|depth|inlineStyleRanges|entityRanges|data|350050|在php.ini中删除‘；’(冒号)包含以下配置：第一个(取消注释并添加配置)：include_path+=“C：\php\”|offset|length|style|BOLD|350051|uncomment(取消注释)：extension_dir+=+"ext“|350052|扩展名(取消注释并编辑配置)：=C:/php//php_mysql.dll+extension=C:/PHP/ext/php_mysqli.dll|350053|350054|重新启动IIS服务器|ordered-list-item|350055|确保mysql正在系统上运行。|350056|350057|如何加载php.ini文件|350058|开发将文件php.ini+-|350059|/+php.ini+-php.ini中的任何一个从C：\PHP重命名为服务器(请注意，扩展名现在将为ini，即重命名为php.ini文件重启服务器|350060|请参阅http://localhost/phpinfo.php|350061|中的更改|350062|entityMap|0|LINK|mutability|MUTABLE|url|http://localhost/phpinfo.php^0|0|P|3|0|0|9|0|F|8|0|0|0|0|0|0|0|0|3|S|0|0|0^^$0|@$1|2|3|4|5|6|7|1A|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|1B|8|@$D|1C|E|1D|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|1E|8|@$D|1F|E|1G|F|G]]|9|@]|A|$]]|$1|J|3|K|5|6|7|1H|8|@$D|1I|E|1J|F|G]]|9|@]|A|$]]|$1|L|3|-4|5|6|7|1K|8|@]|9|@]|A|$]]|$1|M|3|N|5|O|7|1L|8|@]|9|@]|A|$]]|$1|P|3|Q|5|O|7|1M|8|@]|9|@]|A|$]]|$1|R|3|-4|5|6|7|1N|8|@]|9|@]|A|$]]|$1|S|3|T|5|6|7|1O|8|@]|9|@]|A|$]]|$1|U|3|V|5|6|7|1P|8|@]|9|@]|A|$]]|$1|W|3|X|5|O|7|1Q|8|@]|9|@]|A|$]]|$1|Y|3|Z|5|O|7|1R|8|@]|9|@$D|1S|E|1T|1|1U]]|A|$]]|$1|10|3|11|5|6|7|1V|8|@]|9|@]|A|$]]|$1|12|3|-4|5|6|7|1W|8|@]|9|@]|A|$]]]|13|$14|$5|15|16|17|A|$18|19]]]]

How to Enable mysqli in php.ini
<ol>
<li>Edit/uncomment by removing ';'(colon) the following config in php.ini:
1st (uncomment and add config):
<pre><code>include_path = &quot;C:\php\includes&quot;
</code></pre>
2nd (uncomment):
<pre><code>extension_dir = &quot;ext&quot;
</code></pre>
3rd (uncomment and edit config):
<pre><code>extension=C:/PHP/ext/php_mysql.dll
extension=C:/PHP/ext/php_mysqli.dll
</code></pre>
</li>
<li>Restart the IIS server</li>
<li>Make sure that mysql is running on the system.</li>
</ol>
How to load php.ini file
<ol>
<li>Rename any one of the file php.ini-production/php.ini-development to php.ini from C:\PHP(note now the extention will be ini i.e &quot;php.ini&quot;).</li>
<li>After renaming to php.ini file restart server</li>
<li>See the changes in http://localhost/phpinfo.php</li>
</ol>

blocks|key|347460|text|如果你在使用Docker...|type|unstyled|depth|inlineStyleRanges|entityRanges|data|347461|在php-container内部运行：|347462|#docker-php-ext-install+mysqli

#apachectl+restart|code-block|syntax|javascript|347463|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

If you are on Docker...

Inside php-container RUN:

<pre><code>#docker-php-ext-install mysqli

#apachectl restart
</code></pre>

blocks|key|3335621|text|看起来你的安装有问题。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3335622|您是否在php.ini?|3335623|Restarted+Apache和/或-|unordered-list-item|3335624|？|3335625|中激活了MySQLi？|3335626|
|3335627|3335628|3335629|http://www.php.net/manual/en/mysqli.installation.php|offset|length|3335630|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|0|0|0|0|0|0|0|1G|0|0^^$0|@$1|2|3|4|5|6|7|Z|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|10|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|11|8|@]|9|@]|A|$]]|$1|G|3|H|5|F|7|12|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|13|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|14|8|@]|9|@]|A|$]]|$1|M|3|-4|5|F|7|15|8|@]|9|@]|A|$]]|$1|N|3|-4|5|6|7|16|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|17|8|@]|9|@$Q|18|R|19|1|1A]]|A|$]]|$1|S|3|-4|5|6|7|1B|8|@]|9|@]|A|$]]]|T|$U|$5|V|W|X|A|$Y|P]]]]

Seems like problem with your installation. 

<ul>
<li>Have you installed MySQLi? </li>
<li>Have you activated it in php.ini?</li>
<li>Restarted Apache and/or PHP-FPM?</li>
</ul>

<a href="http://www.php.net/manual/en/mysqli.installation.php" rel="nofollow noreferrer">http://www.php.net/manual/en/mysqli.installation.php</a>

blocks|key|3122913|text|我想我可以帮助任何人使用Namesco服务器解决同样的问题。在将数据库从家用pc上的本地服务器移动到namesco后，我一直在尝试解决此问题。他们不会提供帮助，他们说这是一个编码问题。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3122914|然而，从他们在php上托管interface.|3122915|Click的+LINUX上修复|unordered-list-item|3122916|很简单。|3122917|然后点击php模块，从他们的预装模块列表中只需点击mysqli.|3122918|的复选框，然后点击保存。(如果代码在另一台服务器上运行，则无需更改代码。)|3122919|3122920|3122921|不幸的是，他们的支持文章是在浪费时间。读完这篇文章后，我带着新的决心进入了管理界面。|3122922|entityMap^0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|A|$]]|$1|G|3|H|5|F|7|V|8|@]|9|@]|A|$]]|$1|I|3|J|5|F|7|W|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|X|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]|$1|N|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|10|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|R|$]]

I thought I might help anybody with the same problem using Namesco servers.
I have been trying to fix this problem after moving a database from my local server on home pc to namesco. They would not assist they said it was a coding issue.
<ul>
<li>However, it was simple to fix from their CPANEl LINUX hosting
interface.</li>
<li>Click on php.</li>
<li>then click on php modules and from their list of preinstalled modules just click the box for mysqli.</li>
<li>Then click save. (No need to change code if it worked(s) on another server.)</li>
</ul>
Unfortunately, their support articles were a waste of time. After reading this I went to admin interface with a new determination.

blocks|key|346519|text|在全新安装PHP时，在php.ini中先删除;，然后再删除extension_dir。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|346520|entityMap^0|M|1|T|D|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|M|8|@]|D|@]|E|$]]]|G|$]]

On a fresh install of PHP, remove <code>;</code> before <code>extension_dir</code> in php.ini.

blocks|key|345227|text|对于任何使用docker的人，我遇到了这个问题，并通过使用我自己的Dockerfile而不是php:fpm图像解决了这个问题：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|345228|FROM+php:fpm

RUN+docker-php-ext-install+mysqli|code-block|syntax|javascript|345229|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

For anyone using docker, I ran into this issue, and resolved it by using my own Dockerfile instead of the php:fpm image:

<pre><code>FROM php:fpm

RUN docker-php-ext-install mysqli
</code></pre>

blocks|key|3335684|text|有些发行版(比如Gentoo)支持多个PHP安装，您必须确保使用的是安装并启用了mysqli的安装。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3335685|在Gentoo上，我安装了一个新的PHP+(启用了mysqli+USE标志)，但我需要激活新版本的PHP+(因为旧版本肯定缺少mysqli)：|3335686|#+eselect+php+list+apache2
++[1]+++php5.3+*
++[2]+++php5.5
#+eselect+php+set+apache2+2
You+have+to+run+`/etc/init.d/apache2+restart'+for+the+changes+to+take+effect
#+/etc/init.d/apache2+restart|code-block|syntax|javascript|3335687|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikipedia.org/wiki/Gentoo_Linux^0|8|6|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]]|C|$]]|$1|D|3|E|5|6|7|W|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|X|8|@]|9|@]|C|$I|J]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]]]

Some distributions (such as <a href="http://en.wikipedia.org/wiki/Gentoo_Linux" rel="nofollow">Gentoo</a>) support multiple installations of PHP, and you have to make sure you're using one with mysqli installed and enabled.

On Gentoo, I had installed a new PHP (with the mysqli USE flag enabled), but I needed to activate the new version of PHP (since the old one must have been missing mysqli):

<pre><code># eselect php list apache2
 [1] php5.3 *
 [2] php5.5
# eselect php set apache2 2
You have to run `/etc/init.d/apache2 restart' for the changes to take effect
# /etc/init.d/apache2 restart
</code></pre>

blocks|key|3335791|text|我检查了上面的所有内容，但对我来说不起作用。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3335792|我找到了一些步骤。|3335793|我在Ubuntu14.04上使用了PHP版本5.5.9-1ubuntu4.17|offset|length|style|BOLD|3335794|首先检查文件夹|3335795|#ls+/etc/php5/mods-available/
json.ini++mcrypt.ini++mysqli.ini++mysql.ini++mysqlnd.ini++opcache.ini++pdo.ini++pdo_mysql.ini++readline.ini++xcache.ini|code-block|syntax|javascript|3335796|如果它不包含mysqli.ini，请阅读有关安装它其他答案，|3335797|打开php.ini+find+extension_dir|CODE|3335798|在我的例子中，我必须设置extension_dir+=+/usr/lib/php5/20121212|3335799|并重新启动apache2：/ect/init.d/apache2+restart|3335800|entityMap^0|0|0|2|B|H|M|0|0|0|6|A|0|2|7|F|D|0|C|12|0|D|R|0^^$0|@$1|2|3|4|5|6|7|11|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|12|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|13|8|@$F|14|G|15|H|I]|$F|16|G|17|H|I]]|9|@]|A|$]]|$1|J|3|K|5|6|7|18|8|@]|9|@]|A|$]]|$1|L|3|M|5|N|7|19|8|@]|9|@]|A|$O|P]]|$1|Q|3|R|5|6|7|1A|8|@$F|1B|G|1C|H|I]]|9|@]|A|$]]|$1|S|3|T|5|6|7|1D|8|@$F|1E|G|1F|H|U]|$F|1G|G|1H|H|I]]|9|@]|A|$]]|$1|V|3|W|5|6|7|1I|8|@$F|1J|G|1K|H|U]]|9|@]|A|$]]|$1|X|3|Y|5|6|7|1L|8|@$F|1M|G|1N|H|U]]|9|@]|A|$]]|$1|Z|3|-4|5|6|7|1O|8|@]|9|@]|A|$]]]|10|$]]

I checked all above and it didn't work for me,

There are some steps I found.

I used PHP Version 5.5.9-1ubuntu4.17 on Ubuntu 14.04

First check the folder

<pre><code>#ls /etc/php5/mods-available/
json.ini mcrypt.ini mysqli.ini mysql.ini mysqlnd.ini opcache.ini pdo.ini pdo_mysql.ini readline.ini xcache.ini
</code></pre>

If it did not contain mysqli.ini, read other answer for installing it,

Open <code>php.ini</code> find extension_dir 

In my case , I must set <code>extension_dir = /usr/lib/php5/20121212</code>

And restart apache2 : <code>/ect/init.d/apache2 restart</code>

blocks|key|3335857|text|PHP+zip包含\ext目录下的大多数常用扩展名(php_mysqli.dll等windows上的*.dll)，但是默认情况下不启用它们。在尝试使用MySQLi时，您可能会收到此致命错误：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3335858|(+!+)+Fatal+error:+Uncaught+Error:+Class+'mysqli'+not+found+in+C:\myProject\+class.Database.php+on+line+24|code-block|syntax|javascript|3335859|要启用扩展，请打开php.ini+(您可能需要首先将php.ini-development复制为php.ini)，然后取消注释(或添加)以下两行：|3335860|extension_dir+=+"ext"|3335861|以及你得到致命错误的任何特定扩展，例如mysqli：|3335862|extension=mysqli|3335863|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

The PHP zip includes most of the commonly used extensions (*.dll on windows such as php_mysqli.dll) under the \ext directory, however they are not enabled by default. You might be getting this Fatal Error when trying to use MySQLi:

<pre><code>( ! ) Fatal error: Uncaught Error: Class 'mysqli' not found in C:\myProject\ class.Database.php on line 24
</code></pre>

To enable extensions, open php.ini (you might need to first copy php.ini-development as php.ini), and un-comment (or add) these two lines:

<pre><code>extension_dir = "ext"
</code></pre>

And any particular extensions you are getting Fatal Errors for, i.e. for mysqli:

<pre><code>extension=mysqli
</code></pre>

blocks|key|3122997|text|在ubuntu上：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3122998|sudo+apt-get+install+php-mysql
sudo+service+apache2+restart|code-block|syntax|javascript|3122999|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

on ubuntu:

<pre><code>sudo apt-get install php-mysql
sudo service apache2 restart
</code></pre>

blocks|key|3123006|text|经过长时间的分析，我找到了解决这个问题的办法。在使用命令行功能正确测试我的php安装后，我发现php运行良好，可以与mysql数据库一起工作。顺便说一句。你可以用php+-f+filename.php命令用php代码运行代码文件。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3123007|所以我意识到，一定是阿帕奇出了什么问题。|3123008|我创建了一个只包含phpinfo()函数的文件。|3123009|我在这里看到了，在队伍里|3123010|加载的配置文件|offset|length|style|BOLD|3123011|我的配置文件没有加载，而是提到了(无)。|3123012|最后，我在Apache配置中找到了以下条目|3123013|<IfModule+php5_module>
++++PHPINIDir+"C:/xampp/php"
</IfModule>|code-block|syntax|javascript|3123014|但是我已经安装了PHP7，所以Apache无法加载php.ini文件，因为没有对应的条目。我添加了|3123015|<IfModule+php7_module>
++++PHPINIDir+"C:/xampp/php"
</IfModule>|3123016|在重启后，Apache一切运行正常。|3123017|上面这些代码块是我在httpd-xampp.conf文件中找到的。希望它在您的配置中的其他位置。|3123018|在同一个文件中，我已经更改了php7的设置，以替换php5版本。|3123019|#
#+PHP-Module+setup
#
#LoadFile+"C:/xampp/php/php5ts.dll"
#LoadModule+php5_module+"C:/xampp/php/php5apache2_4.dll"
LoadFile+"C:/xampp/php/php7ts.dll"
LoadModule+php7_module+"C:/xampp/php/php7apache2_4.dll"|3123020|如您所见，我已经安装了xampp包，但这个问题只出现在Apache这一端。|3123021|entityMap^0|0|0|0|0|0|7|0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|1C|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|1D|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|1E|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|1F|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|1G|8|@$J|1H|K|1I|L|M]]|9|@]|A|$]]|$1|N|3|O|5|6|7|1J|8|@]|9|@]|A|$]]|$1|P|3|Q|5|6|7|1K|8|@]|9|@]|A|$]]|$1|R|3|S|5|T|7|1L|8|@]|9|@]|A|$U|V]]|$1|W|3|X|5|6|7|1M|8|@]|9|@]|A|$]]|$1|Y|3|Z|5|T|7|1N|8|@]|9|@]|A|$U|V]]|$1|10|3|11|5|6|7|1O|8|@]|9|@]|A|$]]|$1|12|3|13|5|6|7|1P|8|@]|9|@]|A|$]]|$1|14|3|15|5|6|7|1Q|8|@]|9|@]|A|$]]|$1|16|3|17|5|T|7|1R|8|@]|9|@]|A|$U|V]]|$1|18|3|19|5|6|7|1S|8|@]|9|@]|A|$]]|$1|1A|3|-4|5|6|7|1T|8|@]|9|@]|A|$]]]|1B|$]]

I found a solution for this problem after a long analysing procedure.
After properly testing my php installation with the command line features I found out that the php is working well and could work with the mysql database. Btw. you can run code-files with php code with the command php -f filename.php 
So I realized, it must something be wrong with the Apache. 
I made a file with just the phpinfo() function inside. 
Here I saw, that in the line 
Loaded Configuration File 
my config file was not loaded, instead there was mentioned (none). 
Finally I found within the Apache configuration the entry
<pre><code>&lt;IfModule php5_module&gt;
 PHPINIDir &quot;C:/xampp/php&quot;
&lt;/IfModule&gt;
</code></pre>
But I've installed the PHP 7 and so the Apache could not load the php.ini file because there was no entry for that.
I added
<pre><code>&lt;IfModule php7_module&gt;
 PHPINIDir &quot;C:/xampp/php&quot;
&lt;/IfModule&gt;
</code></pre>
and after restart Apache all works well.
These code blocks above I found in my httpd-xampp.conf file. May it is somewhere else at your configuration. 
In the same file I had changed before the settings for the php 7 as replacement for the php 5 version.
<pre><code>#
# PHP-Module setup
#
#LoadFile &quot;C:/xampp/php/php5ts.dll&quot;
#LoadModule php5_module &quot;C:/xampp/php/php5apache2_4.dll&quot;
LoadFile &quot;C:/xampp/php/php7ts.dll&quot;
LoadModule php7_module &quot;C:/xampp/php/php7apache2_4.dll&quot;
</code></pre>
As you can see I have the xampp package installed but this problem was just on the Apache side.

blocks|key|345218|text|在Debian10上|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|345219|apt+install+php-mysql

/etc/init.d/apache2+restart|code-block|syntax|javascript|345220|entityMap^0|1|8|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

on Debian 10 

<pre><code>apt install php-mysql

/etc/init.d/apache2 restart
</code></pre>

blocks|key|3123108|text|通过PHP安装phpXX-extension。在我的FreeBSD案例中：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3123109|pkg+install+php74-extensions|code-block|syntax|javascript|3123110|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

install
phpXX-extension by PHP.
In my FreeBSD's case:
<pre><code>pkg install php74-extensions
</code></pre>

blocks|key|345243|text|我正在使用xampp，我的问题在我重命名后被修复了：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|345244|extension_dir+=+"ext"|code-block|syntax|javascript|345245|至|345246|extension_dir+=+"C:\xampp\php\ext"|345247|附言:别忘了在做这个修改后重新启动apache！|345248|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

I'm using xampp and my problem was fixed once i rename:
<pre><code>extension_dir = &quot;ext&quot;
</code></pre>
to
<pre><code>extension_dir = &quot;C:\xampp\php\ext&quot;
</code></pre>
PS: Don't forget to restart apache after making this change!

blocks|key|3123160|text|在php.ini中：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3123161|extension_dir+="c:/wamp64/bin/php/php7.4.9/ext/"|code-block|syntax|javascript|3123162|确保PHP版本是正确的。|3123163|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

In php.ini :
<pre><code>extension_dir =&quot;c:/wamp64/bin/php/php7.4.9/ext/&quot;
</code></pre>
Make sure the PHP version is correct.

blocks|key|3123198|text|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3123199|打开您的PHP文件夹。|ordered-list-item|3123200|找到php.ini-+;extension=mysqli|offset|length|style|CODE|3123201|delete并打开它。|3123202|找到;+symbol|3123203|保存文件，并将文件扩展名从php.ini-development更改为服务器，然后测试代码：<代码>H214<代码>G215|3123204|3123205|++++if+(!function_exists('mysqli_init')+&&+!extension_loaded('mysqli'))+{++
++++++++++++echo+'We+don\'t+have+mysqli!!!';++
+++++}+else+{++
+++++++++echo+'mysqli+is+installed';
+++++}|code-block|syntax|javascript|3123206|3123207|如果不起作用，请将extension_dir中的php.ini从"ext“更改为"c:\php\ext”，将extension=mysqli更改为extension=php_mysqli.dll，然后再次测试记住每次执行时都要重置服务器|BOLD|3123208|3123209|entityMap^0|0|0|B|H|0|0|2|1|0|0|0|0|0|2W|E|0|0^^$0|@$1|2|3|-4|4|5|6|12|7|@]|8|@]|9|$]]|$1|A|3|B|4|C|6|13|7|@]|8|@]|9|$]]|$1|D|3|E|4|C|6|14|7|@$F|15|G|16|H|I]]|8|@]|9|$]]|$1|J|3|K|4|C|6|17|7|@]|8|@]|9|$]]|$1|L|3|M|4|C|6|18|7|@$F|19|G|1A|H|I]]|8|@]|9|$]]|$1|N|3|O|4|C|6|1B|7|@]|8|@]|9|$]]|$1|P|3|-4|4|5|6|1C|7|@]|8|@]|9|$]]|$1|Q|3|R|4|S|6|1D|7|@]|8|@]|9|$T|U]]|$1|V|3|-4|4|5|6|1E|7|@]|8|@]|9|$]]|$1|W|3|X|4|C|6|1F|7|@$F|1G|G|1H|H|Y]]|8|@]|9|$]]|$1|Z|3|-4|4|5|6|1I|7|@]|8|@]|9|$]]|$1|10|3|-4|4|5|6|1J|7|@]|8|@]|9|$]]]|11|$]]

<ol>
<li>Open your PHP folder.</li>
<li>Find php.ini-development and open it.</li>
<li>Find <code>;extension=mysqli</code></li>
<li>delete the <code>;</code> symbol</li>
<li>save file and change the file extension from php.ini-development to php.ini</li>
<li>Restart the server and test the code:</li>
</ol>
<pre><code> if (!function_exists('mysqli_init') &amp;&amp; !extension_loaded('mysqli')) { 
 echo 'We don\'t have mysqli!!!'; 
 } else { 
 echo 'mysqli is installed';
 }
</code></pre>
<ol start="7">
<li>if it not working, change both extension_dir in php.ini from &quot;ext&quot; to &quot;c:\php\ext&quot;
and extension=mysqli to extension=php_mysqli.dll then test again
Remember to reset the server every time you test</li>
</ol>

blocks|key|3336156|text|您所要做的就是进入php.ini文件，然后在926行(取决于版本)上删除#。它应该看起来像这样：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3336157|;extension=ldap
;extension=mbstring
;extension=exif
extension=mysqli
;extension=oci8_12c
;extension=odbc|code-block|syntax|javascript|3336158|保存文件并以管理员身份打开控制台(cmd)。转到路径Apache24+/+bin并输入httpd+-k+restart。此命令将重新启动服务器。在此之后，刷新页面，一切都应该正常工作。|3336159|entityMap^0|9|7|0|0|Q|E|17|G|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]]|D|@]|E|$]]|$1|M|3|-4|5|6|7|X|8|@]|D|@]|E|$]]]|N|$]]

All you have to do is go to the <code>php.ini</code> file and on line 926 (depending on version) delete #. It should look like this:
<pre><code>;extension=ldap
;extension=mbstring
;extension=exif
extension=mysqli
;extension=oci8_12c
;extension=odbc
</code></pre>
Save the file and open console (cmd) as administrator. Go to the path <code>Apache24 / bin</code> and enter <code>httpd -k restart</code>. This command will restart your server. After that, refresh the page and everything should work.

blocks|key|346609|text|当我尝试我的PHP+web应用程序时，它给出了同样的错误。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|346610|通过谷歌搜索，我发现我的安装中缺少服务器的MySQL插件。我使用的是Ubuntu，所以当我尝试MySQL插件的时候，我发现有2个。|346611|php-mysql和php<version>-mysql|offset|length|style|CODE|346612|我在我的终端上发出了命令-+php+--version，我有php7.4，|346613|我再次发出了apt+install+php7.4-mysql|346614|啊，真灵。|346615|entityMap^0|0|0|0|9|A|I|0|E|D|0|6|O|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|S|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|T|8|@$F|U|G|V|H|I]|$F|W|G|X|H|I]]|9|@]|A|$]]|$1|J|3|K|5|6|7|Y|8|@$F|Z|G|10|H|I]]|9|@]|A|$]]|$1|L|3|M|5|6|7|11|8|@$F|12|G|13|H|I]]|9|@]|A|$]]|$1|N|3|O|5|6|7|14|8|@]|9|@]|A|$]]|$1|P|3|-4|5|6|7|15|8|@]|9|@]|A|$]]]|Q|$]]

When I tried my PHP web app it was giving me the same error.
By googling I found out the MySQL plugin for the PHP server was missing with my installation. I am using Ubuntu, so when I tried MySQL plugin for PHP I found out 2 are there,
<code>php-mysql</code> and <code>php&lt;version&gt;-mysql</code>
I issued command - <code>php --version</code> in my terminal, I was having php7.4,
again I issued <code>apt install php7.4-mysql</code>
It worked.

blocks|key|3336207|text|此问题也可能是由.htaccess文件配置错误引起的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3336208|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

This issue can be also caused by the .htaccess file misconfiguration.

blocks|key|349974|text|<?php++/*+If+the+error+is+due+to+calling+mysqli+in+a+class+*/

++++class+dbconnect+extends+mysqli{

++++++++private+$host+=+'localhost';
++++++++private+$user+=+'root';
++++++++private+$pass+=+'';
++++++++private+$db+=+'test';

++++++++public+function+__construct()+{
++++++++++++parent::__construct($this->host,+$this->user,+$this->pass,+$this->db);

++++++++++++if+(mysqli_connect_error())+{
++++++++++++++++die('Connect+Error+('+.+mysqli_connect_errno()+.+')+'+.
++++++++++++++++++++mysqli_connect_error());
++++++++++++}
++++++++}
++++}
?>|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|349975|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>&lt;?php /* If the error is due to calling mysqli in a class */

 class dbconnect extends mysqli{

 private $host = 'localhost';
 private $user = 'root';
 private $pass = '';
 private $db = 'test';

 public function __construct() {
 parent::__construct($this-&gt;host, $this-&gt;user, $this-&gt;pass, $this-&gt;db);

 if (mysqli_connect_error()) {
 die('Connect Error (' . mysqli_connect_errno() . ') ' .
 mysqli_connect_error());
 }
 }
 }
?&gt;
</code></pre>

I am doing a tutorial and am getting this error:

<blockquote>
 Fatal error: Class 'MySQLi' not found (LONG URL) on line 8
</blockquote>

The code on line 8 is:

<pre><code>$mysqli = new MySQLi($db_server, $db_user, $db_pass, $db_name);
</code></pre>

I saw online someone said to see if it was turned on in my phpinfo(), but there wasn't anything listed in there under for "mysqli".

Also, I am running PHP version 5.2.5

How to solve "Fatal error: Class 'MySQLi' not found"?

数据库

服务器

FreeBSD

Docker

Ubuntu

Gentoo

MySQL

我正在做一个教程，我得到了这个错误：致命错误:在第8行找不到类'MySQLi‘(长URL)第8行的代码是：$mysqli = new MySQLi($db_server, $db_user, $db_pass, $db_name);我在网上看到有人说要看看我的phpinfo()中是否打开了它，但在"mysqli“下面没有列出任何东西。另外，我运行的是PHP版本5.2.5

问如何解决“致命错误:找不到类'MySQLi‘”？
EN

回答 26

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何解决“致命错误:找不到类'MySQLi‘”？EN

回答 26

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何解决“致命错误:找不到类'MySQLi‘”？
EN