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

I am doing a tutorial and am getting this error:

Fatal error: Class 'MySQLi' not found (LONG URL) on line 8

The code on line 8 is:

$mysqli = new MySQLi($db_server, $db_user, $db_pass, $db_name);

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

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

#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

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

Open php.ini find extension_dir

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

And restart apache2 : /ect/init.d/apache2 restart

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:

extension_dir = "C:\software\php\dist\ext"

This made it work for me.

Some distributions (such as Gentoo) 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):

# 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

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

FROM php:fpm

RUN docker-php-ext-install mysqli

install phpXX-extension by PHP. In my FreeBSD's case:

pkg install php74-extensions

1. Open your PHP folder.
2. Find php.ini-development and open it.
3. Find ;extension=mysqli
4. delete the ; symbol
5. save file and change the file extension from php.ini-development to php.ini
6. Restart the server and test the code:

    if (!function_exists('mysqli_init') && !extension_loaded('mysqli')) {  
            echo 'We don\'t have mysqli!!!';  
     } else {  
         echo 'mysqli is installed';
     }

7. if it not working, change both extension_dir in php.ini from "ext" to "c:\php\ext" and extension=mysqli to extension=php_mysqli.dll then test again Remember to reset the server every time you test

In php.ini :

extension_dir ="c:/wamp64/bin/php/php7.4.9/ext/"

Make sure the PHP version is correct.

on ubuntu:

sudo apt-get install php-mysql
sudo service apache2 restart

My OS is Ubuntu. I solved this problem by using:

sudo apt-get install php5-mysql

On a fresh install of PHP, remove ; before extension_dir in php.ini.

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

<IfModule php5_module>
    PHPINIDir "C:/xampp/php"
</IfModule>

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

<IfModule php7_module>
    PHPINIDir "C:/xampp/php"
</IfModule>

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.

#
# 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"

As you can see I have the xampp package installed but this problem was just on the Apache side.

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.

• However, it was simple to fix from their CPANEl LINUX hosting interface.
• Click on php.
• then click on php modules and from their list of preinstalled modules just click the box for mysqli.
• Then click save. (No need to change code if it worked(s) on another server.)

Unfortunately, their support articles were a waste of time. After reading this I went to admin interface with a new determination.

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:

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

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:

extension_dir = "ext"

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

extension=mysqli

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

if (!function_exists('mysqli_init') && !extension_loaded('mysqli')) {
    echo 'We don\'t have mysqli!!!';
} else {
    echo 'Phew we have it!';
}

<?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());
            }
        }
    }
?>

If you are on Ubuntu, run:

 sudo apt-get install php-mysqlnd

on Debian 10

apt install php-mysql

/etc/init.d/apache2 restart

How to Enable mysqli in php.ini

1. Edit/uncomment by removing ';'(colon) the following config in php.ini: 1st (uncomment and add config):

   include_path = "C:\php\includes"
   

   2nd (uncomment):

   extension_dir = "ext"
   

   3rd (uncomment and edit config):

   extension=C:/PHP/ext/php_mysql.dll
   extension=C:/PHP/ext/php_mysqli.dll
   

2. Restart the IIS server
3. Make sure that mysql is running on the system.

How to load php.ini file

1. 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 "php.ini").
2. After renaming to php.ini file restart server
3. See the changes in http://localhost/phpinfo.php

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

<?php 
$mysqli = new \MySQLi($db_server, $db_user, $db_pass, $db_name);

Seems like problem with your installation.

• Have you installed MySQLi?
• Have you activated it in php.ini?
• Restarted Apache and/or PHP-FPM?

http://www.php.net/manual/en/mysqli.installation.php

If you are on Docker...

Inside php-container RUN:

#docker-php-ext-install mysqli

#apachectl restart

I'm using xampp and my problem was fixed once i rename:

extension_dir = "ext"

to

extension_dir = "C:\xampp\php\ext"

PS: Don't forget to restart apache after making this change!