connect php with mysql and configuration

After installing MYSQL, we need to uncomment the following lines
extension=php_mysql.dll and extension=php_mysqli.dll
in php.ini file and restart the apache2 web server.
But when I finish it, it doesn't work.
It shows "Fatal error: Call to undefined function mysql_connect() in……" when I run my php file.
We also need to add something in the path.
computer->properties->advanced system settings->advanced->environment variables->system variables->path->edit->add "C:\php;C:\php\ext" at the end and save it. At last, restart the computer.
It will work!