將mysql_fetch_array更改爲PDO等效

Question

<?php 

$sql="SELECT * FROM products WHERE id_product IN ("; 

foreach($_SESSION['cart'] as $id => $value) { 
    $sql.=$id.","; 
} 

$sql=substr($sql, 0, -1).") ORDER BY name ASC"; 
$query=mysql_query($sql); 
$totalprice=0; 

while ($row=mysql_fetch_array($query)){ 
    $subtotal=$_SESSION['cart'][$row['id_product']]['quantity']*$row['price']; 
    $totalprice+=$subtotal; 
    ?> 
    <tr> 
     <td><?php echo $row['name'] ?></td> 
    <td><input type="text" name="quantity[<?php echo $row['id_product'] ?>]" size="5" value="<?php echo $_SESSION['cart'][$row['id_product']]['quantity'] ?>" /></td> 
    <td><?php echo $row['price'] ?>$</td> 
    <td><?php echo $_SESSION['cart'][$row['id_product']]['quantity']*$row['price'] ?>$</td> 
    </tr> 
    <?php    
    } 
?> 
<tr> 
    <td>Total Price: <?php echo $totalprice ?></td> 
</tr> 

這是我目前使用的代碼。 我得到明顯的錯誤是：

Fatal error: Uncaught Error: Call to undefined function mysql_query()

我知道我需要將其更改爲PDO，但我不知道該怎麼用，同時還得到我想要的totalprice更換mysql_fetch_array。
將其更改爲在此之後：

foreach($_SESSION['cart'] as $id => $value) { 
    $sql.=$id.","; 
} 

$sql=substr($sql, 0, -1).") ORDER BY name ASC"; 
$stmt = $db->prepare($sql); 
$stmt->execute(); 
$totalprice=0; 

我不確定如何進行，同時還得到正確的總價

Answer 1

$sql="SELECT * FROM products WHERE id_product IN ("; 

foreach($_SESSION['cart'] as $id => $value) { 
    $sql.=$id.","; 
} 

$sql=substr($sql, 0, -1).") ORDER BY name ASC"; 
$stmt = $db->prepare($sql); 
$stmt->execute(); 
$totalprice=0; 

$result = $stmt->fetchAll(PDO::FETCH_ASSOC); # FOr mysql_fetch_assoc 

foreach ($result as $index=>$arr) { 
    // $val = $arr['key']; 
} 

純MySQL的方式：

while ($row = $stmt->fetch(PDO::FETCH_ASSOC) { 
    // $val = $row['key']; 
} 

對於mysql_fetch__array：

您可以使用PDO :: FETCH_NUM

鏈接：http://php.net/manual/en/pdostatement.fetchall.php

http://micmap.org/php-by-example/manual/de/pdostatement.fetch.html