Display files and catalogs

The best option is to store file hierarchy and file names in the database. This way you can quickly search for a certain file. Files itself can be stored in some folder on the web server, there is no need to move them to the database.

OK!

It gives me the search function, but only by filename?

Do you mean manually databaseinput of filename and extention?

What about directory search and drilldown?
Found a way to echo dir-list to a text file and then import the file names to a database field.

This gives me oportunity to crate an automatic update in case of new files.

Tough, this only solve the filesearch.
What about "tables/fields" to handle mother/child views for drilldown the directory structure?

You need to store folders hierarchy in the database as well.
Another option - you can find ready made script that will handle this job for you. See some examples at http://www.codango.com/asp/dir/webapps/fileoper/