108
votes

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

25
You can use a handwritten MYSQLi class, so you don't need to install mysqli. It's the only solution if you don't own the server. - chickens
On PHP 7.4 at least the class name is lowercase new mysqli() - undefined

25 Answers

94
votes

Sounds like you just need to install MySQLi.

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.

48
votes

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!';
}
39
votes

If you are on Ubuntu, run:

 sudo apt-get install php-mysqlnd
26
votes

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);
15
votes

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.

5
votes

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

sudo apt-get install php5-mysql
3
votes

If you are on Docker...

Inside php-container RUN:

#docker-php-ext-install mysqli

#apachectl restart
2
votes

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

2
votes

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
1
votes

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

1
votes

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
1
votes

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.

0
votes

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
0
votes

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

0
votes

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
0
votes

on ubuntu:

sudo apt-get install php-mysql
sudo service apache2 restart
0
votes

on Debian 10

apt install php-mysql

/etc/init.d/apache2 restart
0
votes

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.

0
votes

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

pkg install php74-extensions
0
votes

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!

0
votes

In php.ini :

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

Make sure the PHP version is correct.

0
votes
  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';
     }
  1. 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
0
votes

All you have to do is go to the php.ini file and on line 926 (depending on version) delete #. It should look like this:

;extension=ldap
;extension=mbstring
;extension=exif
extension=mysqli
;extension=oci8_12c
;extension=odbc

Save the file and open console (cmd) as administrator. Go to the path Apache24 / bin and enter httpd -k restart. This command will restart your server. After that, refresh the page and everything should work.

0
votes

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,

php-mysql and php<version>-mysql

I issued command - php --version in my terminal, I was having php7.4,

again I issued apt install php7.4-mysql

It worked.

-2
votes
<?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());
            }
        }
    }
?>