wordpress wpdb query

using this code:

// http://codex.ww.wp.xz.cn/Displaying_Posts_Using_a_Custom_Select_Query

 $querystr = "
    SELECT wposts.*
    FROM $wpdb->posts wposts, $wpdb->postmeta wpostmeta
    WHERE wposts.post_title LIKE '%hello%'
    AND wposts.post_type = 'post'
    AND wposts.post_status = 'publish'
 ";

 $pageposts = $wpdb->get_results($querystr);

check result here:
http://demo.htmltiger.com/wpmovie/?page_id=8

answer will be one “Hello world!” post.
but there is 8 posts with same title.

at this page, total 10 time.
http://demo.htmltiger.com/wpmovie/?page_id=10