I am using b2evo 0.92 and I am looking for a SQL-Query which displays the comments made per day.

Like this one:

$sql = "SELECT ID , post_title, post_urltitle, post_issue_date
    FROM evo_posts
    INNER JOIN evo_postcats ON ID = postcat_post_ID
    INNER JOIN evo_categories ON postcat_cat_ID = cat_ID
    WHERE cat_blog_ID = '7'
    AND post_status = 'published'
    GROUP BY ID
    ORDER BY RAND()
    LIMIT $limit";

This statement fetches the published articles and randomizes them. What would be a good statement for the comments per day? I want to know when the most people make comments.

What do you think?