Joining postmeta and posts table to get image URLs

I’m trying to get the image url and ID for images attached to a particular post from the post meta table, joining onto the posts table using the Query below.

The query as it stands returns an empty set. If I remove the WHERE posts.post_parent = $intPostId clause, it returns all the image attachments, which is nearly what I want — but too much!

What change do I need to make to the query to get the data I want?

// $intPostID contains the post ID of the post where all the images are attached.

SELECT
	meta.post_id AS image_id, meta.meta_value AS url
FROM
	$wpdb->posts AS posts LEFT JOIN $wpdb->postmeta AS meta
ON
	posts.ID = meta.post_id
WHERE
	posts.post_parent = $intPostId
AND
	meta.meta_key = '_wp_attached_file'
ORDER BY
	posts.post_date DESC