id,summary,reporter,owner,description,type,status,priority,milestone,component,version,severity,resolution,keywords,cc
23369,WP_Comment_Query meta query 'count' conflicts with 'group by',heshiming,,"This problem relates to {{{/wp-includes/comment.php}}}, both 3.5.1 and trunk are affected. The following line number refers to the 3.5.1 version. 

At line 195, definition of class {{{WP_Comment_Query}}} , a typical meta query will generate such SQL:

{{{SELECT * FROM wp_comments INNER JOIN wp_commentmeta ON (wp_comments.comment_ID = wp_commentmeta.comment_id) WHERE ( comment_approved = '0' OR comment_approved = '1' ) AND comment_post_ID = 22 AND ( (wp_commentmeta.meta_key = 'my_flag' AND CAST(wp_commentmeta.meta_value AS CHAR) = 'my_value') ) GROUP BY wp_comments.comment_ID ORDER BY comment_date_gmt DESC }}}

Note that at line 357, a meta query will always generate a {{{GROUP BY}}} clause. This works for comment rows. Say that I've got 3 comments matching this query, I'll see each of them in a row:

{{{
comment row 1, data
comment row 2, data
comment row 3, data
}}}

However, this query doesn't work well then {{{$count = true}}}. Note that by specifying {{{$count = true}}}, the function only changes {{{'SELECT *'}}} into {{{'SELECT COUNT(*)'}}}. For 3 comment result, I'm seeing something like this:

{{{
1
1
1
}}}

And you can see, because there's a {{{'GROUP BY'}}} clause. And each comment has a unique ID. The result is 3 'grouped row' of comments, and each will always have count of 1.

Therefore, the result of {{{$wpdb->get_var()}}} will be either 1, or NULL (when nothing is matched). I believe this behavior is not by intention.

To get count working, {{{'GROUP BY'}}} clause must be removed when $count is true.",defect (bug),new,normal,Awaiting Review,Comments,3.5.1,normal,,,