Mysql查询不显示列的总和

Question

任何想法为什么这不起作用？当我运行它时，它不显示任何东西。

$qry = mysql_query(" SELECT SUM(payment_received) AS total FROM Orders "); 
    { 
$row = mysql_fetch_assoc($qry); 
echo $row['total']; 
} 

感谢您的任何帮助。

Answer 1

纠正你用下面的例子

$qry = mysql_query("SELECT SUM(payment_received) AS total FROM Orders"); 
while ($row = mysql_fetch_assoc($qry)) { 
{ 
    echo $row["total"]; 
} 

Answer 2

$result = mysql_query("SELECT SUM(payment_received) AS total FROM Orders") or die(mysql_error()); 
$row = mysql_fetch_assoc($result); 
print_r($row);