SQL and PHP order by with count

Question

I have this following SQL statement / PHP recordset;

$sql_result= mysql_query("SELECT * FROM reports GROUP BY post DESC", $db);
while($rs = mysql_fetch_array($sql_result)) {
    echo "post $rs[post] has $rs[num] reports<br>";
    }

The num field doesn't exist, but I want it to display how many are in that group. I assume it uses a COUNT in the SQL but not sure where.

Any advice?

Answer 1

You use the aggregate COUNT(*) function along with GROUP BY to get per-group counts. And DESC can only be used along with ORDER BY .

SELECT post, COUNT(*) AS num
FROM reports
GROUP BY post
ORDER BY num DESC