MySQL SUM表中的所有值然后回显

Question

Table - Messages
+--------------------------------------------------------------------------------------------+
| msg_id | message | uid_fk | ip | created | uploads|
|  554  Blah....    35     ..  1355000068   0   |
|  555  Blah....    34     ..  1355002587   0   |
|  553  Blah....    34     ..  1354990968   0   |
+--------------------------------------------------------------------------------------------+

我想做的是获取uid_fk并将其总和，然后能够使用php对其进行回显。 uid_fk是另一个表中的用户uid，称为其他用户数据。 我完全不确定如何通过获取它们的特定ID来将两者加起来。

我从这里开始，但是对于MySQL数据库我还是很陌生。

    public function Total_Posts($uid){
        $query          = mysql_query("SELECT uid_fk, sum(count) as sum from messages group by uid_fk");
        $num            = mysql_fetch_array($query);
        $return $num;
}

---

UPDATE: Working Version

    public function Total_Posts($uid){
        $messages       = mysql_query("SELECT * FROM messages WHERE uid_fk='$uid'");
        $numrows        = mysql_num_rows($messages);
        return $numrows;
    }

    <?php 
        $Total_Posts        = $Wall->Total_Posts($uid,$total);
    ?>

    <?php echo $Total_Posts; ?>

Seems to work great, thank you for all the help.

Answer 1

获得您需要的所有元素：

$messages = mysql_query("SELECT * FROM Messages WHERE uid_fk='$uid'");

然后求和：

$sum=0;
while ($message = mysql_fetch_array($messages)){
    $sum += $message['uid_fk'];
}