OwncloudBookmarksOfficial/appinfo/migrate.php

<?php
class OC_Migration_Provider_Bookmarks extends OC_Migration_Provider{
	
	// Create the xml for the user supplied
	function export( ) {
		$options = array(
			'table'=>'bookmarks',
			'matchcol'=>'user_id',
			'matchval'=>$this->uid,
			'idcol'=>'id'
		);
		$ids = $this->content->copyRows( $options );

		$options = array(
			'table'=>'bookmarks_tags',
			'matchcol'=>'bookmark_id',
			'matchval'=>$ids
		);
		
		// Export tags
		$ids2 = $this->content->copyRows( $options );
		
		// If both returned some ids then they worked
		if( is_array( $ids ) && is_array( $ids2 ) ) {
			return true;	
		} else {
			return false;
		}
		
	}
	
	// Import function for bookmarks
	function import( ) {
		switch( $this->appinfo->version ) {
			default:
				// All versions of the app have had the same db structure, so all can use the same import function
				$query = $this->content->prepare( "SELECT * FROM bookmarks WHERE user_id = ?" );
				$results = $query->execute( array( $this->olduid ) );
				$idmap = array();
				while( $row = $results->fetchRow() ) {
					// Import each bookmark, saving its id into the map
					$sql = "INSERT INTO `*PREFIX*bookmarks`
						(`url`, `title`, `user_id`, `public`, `added`, `lastmodified`) VALUES (?, ?, ?, ?, ?, ?)" ;
					$query = OCP\DB::prepare($sql);
					$query->execute(array(
						$row['url'], $row['title'], $this->uid, $row['public'],
						$row['added'], $row['lastmodified']
					) );
					// Map the id
					$idmap[$row['id']] = OCP\DB::insertid();
				}
				// Now tags
				foreach($idmap as $oldid => $newid) {
					$query = $this->content->prepare( "SELECT * FROM bookmarks_tags WHERE bookmark_id = ?" );
					$results = $query->execute( array( $oldid ) );
					while( $row = $results->fetchRow() ) {
						// Import the tags for this bookmark, using the new bookmark id
						$sql = "INSERT INTO `*PREFIX*bookmarks_tags`(`bookmark_id`, `tag`) VALUES (?, ?)";
						$query = OCP\DB::prepare($sql);
						$query->execute( array( $newid, $row['tag'] ) );	
					}		
				}
				// All done!
				break;
		}
		
		return true;
	}
	
}

// Load the provider
new OC_Migration_Provider_Bookmarks( 'bookmarks' );