WP_Query() does not return all entries

I have this query that returns only a few of the entries I have on the table. I have over 10 posts but this query only returns 6. Please help with suggestions



$query = new WP_Query("year=2011&monthnum=09&post_status=publish&post_type=post&orderby=post_date&order=DESC");
while ($query->have_posts()):
$query->the_post();
$title=get_the_Title();
echo"<p><input type=\"checkbox\" name=\"MyArticle[]\" value=\"".get_the_ID()."\">".get_the_Title()."</p>";
endwhile;
wp_reset_query();

Try adding `posts_per_page=-1` to the string of parameters passed to `WP_Query`.

If that value is not set, then it falls back to use the default posts per page option you have set in `Settings >> Reading >> Blog pages show at most`.

My guess is that this value is 6 so its returning that many posts since you did not specify a different limit.

$args = array(
'post_type' => 'product',
'orderby' => 'ASC',
'posts_per_page'=>-1
);
$wp_query = new WP_Query($args);