These answers are provided by our Community. If you find them useful, show some love by clicking the heart. If you run into issues leave a comment, or add your own answer to help others.
PHP should already have PDO extension enabled. What you probably need is the mysql driver for it.
# test if php5-mysql package is installed
dpkg-query --status php5-mysql | grep Status
# install the package if the above command indicates that it is not installed
sudo apt-get install php5-mysql
From GPU-powered inference and Kubernetes to managed databases and storage, get everything you need to build, scale, and deploy intelligent applications.