PHP購物車未顯示眾多產品

Question

我已經制作了一個php購物車，它在主屏幕上顯示了所有產品，您可以單擊它們並將它們添加到購物籃中，然后將您帶到購物車屏幕。 這只會顯示一種產品，但是會顯示您添加了多少種不同的產品，即使它們都有不同的標題。 價格和數量的總和，只有產品名稱沒有。 這是我的代碼。

<?php
session_start();
include "connect.php";
include "header.php";

function viewcart(){
if (isset($_SESSION['cart'])){ //if shopping cart is not empty
    $cart = $_SESSION['cart']; //store the cart array into a variable then display the content
    echo "<table border=\"1\"><tr><th>Product Name</th><th>Quantity</th><th>Delete</th></tr>";
    foreach ($cart as $product=>$quantity){
        $q = "SELECT ID, Name FROM Products";
        $result = mysqli_query($_SESSION['conn'],$q);
        $row = mysqli_fetch_array($result);
        $product_id = $row[0];
        echo "<tr><td>$product</td><td>$quantity</td><td><a href=\"?action=delete&product=$product_id\">-</a></td></tr>";
        mysqli_free_result($result);
    }
    echo "</table>";
    subtotal($cart); //display the subtotal
} else { //if shopping cart is empty
    echo "<p>There is no product in your shopping cart.</p>";
}


}

function addproduct($product_id, $product_qty){

$q = "SELECT ID, Name FROM Products";
$result = mysqli_query($_SESSION['conn'],$q)
 or die("Error: ".mysqli_error($_SESSION['conn']));
$row = mysqli_fetch_array($result);
$product_name = $row[1]; //get the product name from product id because it is better to display name than id in the cart
if (isset($_SESSION['cart'])){ //if shopping cart is not empty
    $cart = $_SESSION['cart'];
    if (array_key_exists($product_name, $cart)){ //if the product exists, update quantity
        $cart[$product_name] += $product_qty;
    } 
    else { //otherwise, add new product-quantity pair to the array
        $cart[$product_name]=$product_qty;
    }
$_SESSION['cart'] = $cart; //write the updated array back to session variable
}
else { //if shopping cart is empty
    $cart = array($product_name=>$product_qty); //add product and quantity to the shopping cart
    $_SESSION['cart'] = $cart; //write the updated array back
}
mysqli_free_result($result);
}

function deleteproduct($product_id, $product_qty){

$q = "SELECT Name FROM Products";
$result = mysqli_query($_SESSION['conn'],$q);
$row = mysqli_fetch_array($result);
$product_name = $row['Name'];
if (isset($_SESSION['cart'])){ //if shopping cart is not empty
    $cart = $_SESSION['cart'];
    if (array_key_exists($product_name, $cart)){ //if the product exists, update quantity
        $cart[$product_name] -= $product_qty;
        if ($cart[$product_name] == 0){ //if the quantity is 0, delete the key
            unset($cart[$product_name]);
        }
    }
    else { //exception
        echo "<p>Error!</p>";
    }
    $_SESSION['cart'] = $cart; //write the updated array back to session variable
} else {
    echo "<p>Error!</p>";
}
mysqli_free_result($result);
}

function emptycart(){

if (isset($_SESSION['cart'])){ //if shopping cart is not empty
    unset($_SESSION['cart']);
}
else {
    echo "<p>Error!</p>";
}
}


function subtotal($cart){ //calculate the total value of products in the shopping cart
$total = 0; //initialise total
if (!empty($cart)){
    foreach ($cart as $product => $quantity){
        $q = "SELECT ID, Price FROM Products";
        $result = mysqli_query($_SESSION['conn'],$q);
        $row = mysqli_fetch_array($result);
        $price = $row['Price'];
        $total += $price * $quantity;
    }
    echo "<p>Total: $total | <a href=\"?action=empty\">Empty cart</a></p>";
} else {
    unset($_SESSION['cart']); //do not need to keep an empty cart, so delete it
    echo "<p>There is no product in your shopping cart.</p>";
}
}


if (isset($_GET['action'])){

if ($_GET['action']=='view'){

    viewcart();

} elseif ($_GET['action']=='add'){
    if (isset($_GET['product'])){
        $product_id = $_GET['product'];
        $product_qty = 1; //default product value
        addproduct($product_id, $product_qty);
        viewcart();
        echo "<p><a href=\"javascript:history.go(-1)\">back</a></p>";
    } else {
        echo "<p>There is an error! Are you trying to attack this little poor shopping cart?</p>";
    }
} elseif ($_GET['action'] == 'delete'){
    if (isset($_GET['product'])){
        $product_id = $_GET['product'];
        $product_qty = 1; //default product value
        deleteproduct($product_id, $product_qty);
        viewcart();
    }
    else {
        echo "<p>There is an error! </p>";
    }
} elseif ($_GET['action']=='empty'){
    emptycart();
    viewcart();
} 

else {
    echo "<p>There is an error! </p>";
}
}
else {
    echo "<p>There is an error! </p>";
}


include "footer.php";

?>

Answer 1

您的查詢中有錯字。 您可能想提取產品的產品ID，但實際上是選擇表中的所有內容。

$q = "SELECT ID, Name FROM Products";

更新它，以讀取類似以下示例的內容，並檢查是否可以解決問題

$q = "SELECT ID, Name FROM `Products` WHERE name='$product' ";

稍后您將讀取結果為

$row = mysqli_fetch_array($result);

我希望您知道，這樣$row只會得到它從表中獲得的第一行。