Importing data from non-wordpress mysql database

You have to create an import php file to get the Questions/Answers from a non-wordpress database and bring them into posts in wordpress.

Question Table

<?php

/// non-wordpress database connection string here

require('./wp-load.php');

$results = mysql_query("SELECT * FROM questions");

while ($row = mysql_fetch_assoc($results)) 
{

    $post_information = array(
	'post_title' => wp_strip_all_tags( $row['question'] ),
	'post_content' => $row['answer'],
	'post_category' =>  array(6,7), // Cat Ids
	'post_date' => date('Y-m-d H:i:s', strtotime( $row['timestamp'] )),
	'post_type' => "post",
	'post_excerpt' => "",
	'post_author' => "admin",
	'post_status' => "publish"
	);
	
	$post_id = wp_insert_post( $post_information );		
	
	$filename = "http://www.domain.com/images/post-image.png";   ////  Post Thumbnail Image
	$wp_filetype = wp_check_filetype(basename($filename), null );
	
	$attachment = array(
	  'post_mime_type' => $wp_filetype['type'],
	  'post_title' => preg_replace('/\.[^.]+$/', '', basename($filename)),
	  'post_content' => '',
	  'post_status' => 'inherit'
	);
	
	$attach_id = wp_insert_attachment( $attachment, $filename, $new_post );
	
	//update_post_meta($post_id,'_thumbnail_id',$attach_id);	
	
	add_post_meta($post_id, '_thumbnail_id', $attach_id, true);

}

?>