SELECT COUNT( n.* ) AS news_count, COUNT( p.* ) AS polls, COUNT( b.* ) AS blogs, COUNT( bc.* ) + COUNT( nc.* ) + COUNT( pc.* ) + COUNT( vc.* ) AS comments
FROM news_article_to_user n, poll p, blog b, video v, comment_blog bc, comment_news nc, comment_poll pc, comment_video vc
WHERE n.user_id =31
AND p.user_id =31
AND b.user_id =31
AND v.user_id =31
AND bc.user_id =31
AND nc.user_id =31
AND pc.user_id =31
AND vc.user_id =31