Question

我有一個數據庫輸出循環。

我需要相乘值$total，結果賦給另一個變量和輸出它。我應該怎麼做？

$quantity來自$_POST。

$items = implode(",",array_keys($_POST)); 

mysql_query('SET NAMES utf8'); 
$query = 'SELECT * FROM 
    items 
WHERE 
    item_id IN (' . $items . ')'; 

$result = mysql_query($query, $db) or die (mysql_error($db)); 

echo ' 

<table id="items"> 
<tr class="head"> 
    <td>Name</td> 
    <td>Cost</td> 
    <td>Quantity</td> 
    <td>Subtotal</td> 
</tr> 

'; 
$total = array(); 
while ($row = mysql_fetch_assoc($result)) { 
echo '<tr class="targetfields">'; 
echo '<td>' . $row['item_name'] . '</td> 

<td>' . $row['item_cost']; 
//Getting item id 
foreach ($_POST as $itemid=>$quantity) 
{ 
//Displayin' quantity 
if ($itemid == $row['item_id']){ 
    echo '</td><td><input name="' . $row['item_id'] . '" class="input-small" size="2" maxlength="2" type="text" value="'; 
    echo "{$quantity}"; 
    echo '" readonly></td> 
    <td>'; $sum = ($row['item_cost'] * $quantity); echo $sum; 
    echo '</td>'; 

    $total.= $sum; 

} 


} 
     echo '</tr>'; 
} 

?> <tr> 
<td class="sum" colspan="4"> Total: 
<?php 



?> </td> 
</tr> 
</table> 

Answer 1

1. $total .= $sum;這不會工作，將其更改爲：$total[] = $sum;
2. 要獲得產品陣列$total使用的所有元素：後while循環array_product

即：

$items = implode(",",array_keys($_POST)); 

mysql_query('SET NAMES utf8'); 
$query = 'SELECT * FROM 
    items 
WHERE 
    item_id IN (' . $items . ')'; 

$result = mysql_query($query, $db) or die (mysql_error($db)); 
$total = array(); 
while ($row = mysql_fetch_assoc($result)) { 

$sum = ($row['item_cost'] * $quantity); echo $sum;  
$total[] = $sum; 

} 

echo array_product($total); 

Ref：http://php.net/manual/en/function.array-product.php

Answer 2

我覺得應該是

$sum = 1; 
while ($row = mysql_fetch_assoc($result)) { 
    $sum = $row['item_cost'] * $sum; 
} 
echo $sum;