从购物车中检索和回显"产品"的简单PHP请求不起作用？

Question

尝试使用它while loop来回显数据库中的prod_qty和prod_desc字段.没有错误.我也试过使用foreach loop你在代码中看到的,但它没有显示任何东西.

这是cart.php文件:

    <?php
// 1. Establish a connection using three functions: 1. mysqli_connect() 2. mysqli_connect_errno() 3. mysqli_connect_error()
    $dbhost = "localhost";
    $dbuser = "root";
    $dbpass = "";
    $dbname = "shoppingcart";

    $connection = mysqli_connect($dbhost, $dbuser, $dbpass, $dbname); 

    // Test if connection occured
    if(mysqli_connect_errno()) {
        die("Database connection failed " . mysqli_connect_error() . "( " . mysqli_connect_errno() . " )");
        }    


    // Show the products by performing a query to database.
    $query = "SELECT prod_desc, prod_qty FROM cart WHERE prod_id = 1 AND prod_id = 2 AND prod_id = 3 ";

    $result = mysqli_query($connection, $query);

    while($cart = mysqli_fetch_assoc($result)) {
        echo $cart["prod_qty"];
        echo $cart["prod_desc"];

    }

    /*if($result) {

        foreach ($result as $cart ) {
            echo $cart["prod_qty"];
            echo $cart["prod_desc"];

        }

        } */

?>

这是我的数据库结构:

我确定我犯了一个愚蠢的错误,因为我没有错误!有什么想法吗？

Answer 1

如果您想获得prod_id1或2或3的记录,可以使用in如下:

$query = "SELECT prod_desc, prod_qty FROM cart WHERE prod_id in (1, 2, 3 )";