Route , remove index.php and use adminer

It should look exactly like that. %{REQUEST_FILENAME} are an internal name in Apache and gets translated into whatever file you try to open.

E.g. adminer.php gets translated into.
RewriteCond adminer.php !-f
RewriteCond adminer.php !-d

E.g. myamazingfile.php gets translated into.
RewriteCond myamazingfile.php !-f
RewriteCond myamazingfile.php !-d

So that you don't need to add hundreds of lines.

Where must i put  this htaccess ? in root or in application or both ?