How is this done? Just as a test, this is what I have in the SQL Query:
SELECT ID,post_title,post_name,post_date,post_content FROM wp_posts WHERE post_type='post' SELECT comment_ID FROM wp_comments WHERE comment_type='comment'
Then in the fields below I've added field name as comment_ID and field label as Comment ID.
When I run this report, it comes out empty.