Show databases records in block

Hi everyone, i'm trying to show database on a custom block in html but i can't do this.

{{$livres_db = \IPS\Db::i()->select( '*', 'cms_custom_database_4', '', 'field_11 DESC' );}}
{{$livres = array();}}
{{foreach $livres as $id => $livre}}
	{{$idField = $livre::$databaseColumnId;}}
    {{$livresIds[] = $livre->$idField;}}
{{endforeach}}

I don't know if I'm on the good way to success. If anybody can help me ^^