Apache application error caused by php connection to database

Php connection to the database causes an error in the apache application. if you click log on, an error occurs in the apache application.
This error occurs when you connect to the database by writing php on any page.

Reply to discussion (solution)

It's really cool. I used to install software in order. now I have to write environment variables in order. I just wiped them.

Solution:
Apache application error caused by php connection to database
Just write a sentence and give it to you.

No ..

Why do we need to modify the environment variable PATH?
Apache, mysql, and php can all be installed in green and do not depend on the registry during running.

You can uninstall it and then install it.

Why do we need to modify the environment variable PATH?
Apache, mysql, and php can all be installed in green and do not depend on the registry during running.
Try it the next time you install the system.

Don't try again. copy your environment this time and run it on a USB flash drive.
Of course, you must delete all the drive letters in the configuration file.