"Could Not Find Driver" Message When Executing Query

I have a Laravel project. It was fine until I updated my Ubuntu 19.04 to 19.10. While testing my APIs on Postman I get this error:

"message": "could not find driver (SQL: select * from `users` where `username` = genesis limit 1)",
"exception": "Illuminate\\Database\\QueryException",
"file": "/home/arkhalis/Repos/laravel/safetrade/vendor/laravel/framework/src/Illuminate/Database/Connection.php",
"line": 664

and after that I tried to run Composer on terminal and got this output

PHP Fatal error:  Uncaught Error: Call to undefined function Symfony\Component\Console\Helper\mb_detect_encoding() in /usr/share/php/Symfony/Component/Console/Helper/Helper.php:50
Stack trace:
#0 /usr/share/php/Symfony/Component/Console/Descriptor/TextDescriptor.php(329): Symfony\Component\Console\Helper\Helper::strlen('h')
#1 /usr/share/php/Symfony/Component/Console/Descriptor/TextDescriptor.php(97): Symfony\Component\Console\Descriptor\TextDescriptor->calculateTotalWidthForOptions(Array)
#2 /usr/share/php/Symfony/Component/Console/Descriptor/TextDescriptor.php(197): Symfony\Component\Console\Descriptor\TextDescriptor->describeInputDefinition(Object(Symfony\Component\Console\Input\InputDefinition), Array)
#3 /usr/share/php/Symfony/Component/Console/Descriptor/Descriptor.php(55): Symfony\Component\Console\Descriptor\TextDescriptor->describeApplication(Object(Composer\Console\Application), Array)
#4 /usr/share/php/Symfony/Component/Console/Helper/DescriptorHelper.php(67): Symfony\Component\Console\Descriptor\Descriptor->describ in /usr/share/php/Symfony/Component/Console/Helper/Helper.php on line 50

Fatal error: Uncaught Error: Call to undefined function Symfony\Component\Console\Helper\mb_detect_encoding() in /usr/share/php/Symfony/Component/Console/Helper/Helper.php:50
Stack trace:
#0 /usr/share/php/Symfony/Component/Console/Descriptor/TextDescriptor.php(329): Symfony\Component\Console\Helper\Helper::strlen('h')
#1 /usr/share/php/Symfony/Component/Console/Descriptor/TextDescriptor.php(97): Symfony\Component\Console\Descriptor\TextDescriptor->calculateTotalWidthForOptions(Array)
#2 /usr/share/php/Symfony/Component/Console/Descriptor/TextDescriptor.php(197): Symfony\Component\Console\Descriptor\TextDescriptor->describeInputDefinition(Object(Symfony\Component\Console\Input\InputDefinition), Array)
#3 /usr/share/php/Symfony/Component/Console/Descriptor/Descriptor.php(55): Symfony\Component\Console\Descriptor\TextDescriptor->describeApplication(Object(Composer\Console\Application), Array)
#4 /usr/share/php/Symfony/Component/Console/Helper/DescriptorHelper.php(67): Symfony\Component\Console\Descriptor\Descriptor->describ in /usr/share/php/Symfony/Component/Console/Helper/Helper.php on line 50

Also I have tried to run composer update and got the same result as this question and run sudo apt-get install php-mbstring but the same result as I run composer command on terminal.

Try to install all the required extension by Laravel. Please take a look here.

You can try to run this command if you're using PHP 7.1:

sudo apt install php7.1 php7.1-fpm php7.1-curl php7.1-mysql php7.1-common php7.1-mbstring php7.1-mcrypt php7.1-xml

Or you can run this command if you're using PHP7.2 (no mcrypt, since it's has been removed)

sudo apt install php7.2 php7.2-fpm php7.2-curl php7.2-mysql php7.2-common php7.2-mbstring php7.2-xml

If you're experiencing an error, maybe you don't have any PHP repo added. Try to add this complete PHP repo by Ondřej Surý.

sudo add-apt-repository ppa:ondrej/php
sudo apt update

Update

Since you're using Ubuntu 19.10 (Eoan), I've heard that by default It comes with PHP 7.3. So, maybe you could try:

sudo apt install php php-fpm php-curl php-mysql php-common php-mbstring php-xml

Right now the ondrej/php still not release any PHP packages for 19.10 (because Ubuntu 19.10 is released recently). It takes time for the author to released the packages.