bp_groups_migrate_invitations()

function bp_groups_migrate_invitations() {
	global $wpdb;
	$bp = buddypress();

	$records = $wpdb->get_results( "SELECT id, group_id, user_id, inviter_id, date_modified, comments, invite_sent FROM {$bp->groups->table_name_members} WHERE is_confirmed = 0 AND is_banned = 0" );
	if ( empty( $records ) ) {
		return;
	}

	$processed = array();
	$values = array();
	foreach ( $records as $record ) {
		$values[] = $wpdb->prepare(
			"(%d, %d, %s, %s, %d, %d, %s, %s, %s, %d, %d)",
			(int) $record->user_id,
			(int) $record->inviter_id,
			'',
			'bp_groups_invitation_manager',
			(int) $record->group_id,
			0,
			( 0 === (int) $record->inviter_id ) ? 'request' : 'invite',
			$record->comments,
			$record->date_modified,
			(int) $record->invite_sent,
			0
		);
		$processed[] = (int) $record->id;
	}

	$table_name = BP_Invitation_Manager::get_table_name();
	$query = "INSERT INTO {$table_name} (user_id, inviter_id, invitee_email, class, item_id, secondary_item_id, type, content, date_modified, invite_sent, accepted) VALUES ";
	$query .= implode(', ', $values );
	$query .= ';';
	$wpdb->query( $query );

	$ids_to_delete = implode( ',', $processed );
	if ( $ids_to_delete ) {
		$wpdb->query( "DELETE FROM {$bp->groups->table_name_members} WHERE ID IN ($ids_to_delete)" );
	}
}