我如何更改此SQL代码，以便将所有添加的价格相互计算并求和？ 我回应$ count6 帮助会非常有用，谢谢
// Total price : projecten > price
$query = "SELECT COUNT(*) as countvar FROM projecten where price;";
$result = mysqli_query($mysqli,$query);
$row = mysqli_fetch_array($result);
$count6= $row['countvar'];
好的，我有
// Total price : projecten > price
$query = "SELECT price, SUM(amount) AS total_amount FROM projecten";
$result = mysqli_query($mysqli,$query);
$row = mysqli_fetch_array($result);
$count6= $row['total_amount'];
我回声$ count6 没事