newbie: activating php to mysql

[system]

Newbie. Running Ubuntu 16.04 Apache2; PHP 7.0.8; mySQL Ver 8.42 Distribution 5.7.13

a localhost/test.php runs in firefox. so, i assume apache is working and so is php. i can check the version on mysql. but, the phpinfo does not show me a mysqli section. is there a way to remedy this without reinstalling?

[astonecipher]

Did you install the MySQL component when installing PHP?

run this and see what happens:

cat /etc/php7.0/conf.d/mysqli.ini

If nothing is found,

sudo apt-get install php7.0-mysql