Subtracting Query Values

[jason360]

Hey guys,

 

I am trying to make two queries providing $result and $result2.  I would like to subtract the two results to create a total for the vote (negative vote being possible).  Therefore on an empty query the result value would have to be zero.

 

My subtraction function isn't working.  Does anyone know what I am doing wrong?  I am getting no result.

 

Thanks in advance!

 

My code:

 

$result = mysql_query('SELECT COUNT(*) FROM comment_votes WHERE vote_com_writer_id = "'.$d['user_id'].'" AND vote_com_rank = "1"');
        $positive_votes = mysql_result($result, 0);


$result2 = mysql_query('SELECT COUNT(*) FROM comment_votes WHERE vote_com_writer_id = "'.$d['user_id'].'" AND vote_com_rank = "2"');
        $negative_votes = mysql_result($result2, 0);


list($vote) = $positive_votes - $negative_votes; 

 

[jason360]

Problem solved:

$result = mysql_query('SELECT COUNT(*) FROM comment_votes WHERE vote_com_writer_id = "'.$d['user_id'].'" AND vote_com_rank = "1"');
        $positive_votes = mysql_result($result, 0);


$result2 = mysql_query('SELECT COUNT(*) FROM comment_votes WHERE vote_com_writer_id = "'.$d['user_id'].'" AND vote_com_rank = "2"');
        $negative_votes = mysql_result($result2, 0);


$vote = $positive_votes - $negative_votes; 

[mac_gyver]

run the following (untested) single query and fetch the total from the result set -

$query = "SELECT SUM(CASE vote_com_rank WHEN 1 THEN 1 WHEN 2 THEN -1 ELSE 0 END) as total FROM comment_votes WHERE vote_com_writer_id = {$d['user_id']}";