If you wish to import data from another wiki running MediaWiki or for that matter from one or several wiki’s on wikipedia then there is a quick way to import page by page.
This functionality is in MediaWiki by default, but needs to be initiated. This is done by adding the following in LocalSettings.php
$wgImportSources = array( 'wikinews', 'wikiquote', 'wikipedia', );
The ImportSources are interwiki links from the database.