循环中的SUM值

In my PHP page, I have a while loop that displays the Total of Orders of Customers Table. I want to get the sum of all the Totals values in while loop. This is how the relevant sections of my code look at the moment:

<?php

include'includes/config.php';
$sql ="Select * from new_booking order by order asc";
$re = mysqli_query($mysqli,$sql);

while($row=mysqli_fetch_array($re)) { 
    $order    =   $row['order'];
    $duration =   12;
    $total = $order * $duration;

    echo " <p> $total </p>";
  // echo "<p> All Sumtotals should display here </p> ";

}

?> 

7*12=84
8*12=96
Sum total = 180

<?php

include'includes/config.php';
$sql ="Select * from new_booking order by order asc";
$re = mysqli_query($mysqli,$sql);
$total = 0;
while($row=mysqli_fetch_array($re)) { 
    $order    =   $row['order'];
    $duration =   12;
    $total = $total + ($order * $duration);


}

    echo " <p> $total </p>";
  // echo "<p> All Sumtotals should display here </p> ";

?> 

Declare $total outside while loop as $total=0, write $total=$total+ ($order*$duration) inside loop

Define a variable before the loop that will contain the sum total of all records:

$sumTotal = 0;

while($row = mysqli_fetch_array($re)) { 
    $order    = $row['order'];
    $duration = 12;
    $total    = $order * $duration;

    // Add this records total to the sum total
    $sumTotal += $total;

    echo "<p> $total </p>";
}    

echo "<p>Here's the sum total: $sumTotal</p>";

This will give you the total for each record and then the sum total of all records after.

If you rather want to see the sum total on each record (to see it increasing), then just echo $sumTotal instead of $total inside the loop.

Keep track of the sum total in a new variable..

<?php

include'includes/config.php';
$sql ="Select * from new_booking order by order asc";
$re = mysqli_query($mysqli,$sql);
$sumTotal = 0;

while($row=mysqli_fetch_array($re)) { 
    $order    =   $row['order'];
    $duration =   12;
    $total = $order * $duration;
    $sumTotal = $sumTotal + $total;
    echo " <p> $total </p>";
    echo " <p> Running total $sumTotal </p>";
}
echo " <p> Grand total $sumTotal </p>";
?> 

If you don't need to print out each total one at a time, you could do this in the SQL statement instead, sum up all the order values (*12) and give it an alias to make it easier to access...

$sql = "SELECT SUM(`order` * 12) AS total FROM new_booking";
$run = mysqli_query($mysqli, $sql);
$row = mysqli_fetch_assoc($run);
echo $row['total'];