Question

我试图阻止用户购买缺货产品。以下代码未显示任何错误，并且即使库存低于零，仍允许用户购买产品。关于我做错了什么的任何建议？

<?php

    $productID= $_GET['ID'];
    $username = $_SESSION['solentuser']; 


    $conn=new PDO("mysql:host=localhost;dbname=user;","user","pass");

    $results=$conn->query("SELECT stocklevel FROM products");
    $row=$results->fetch();

    if($row['stocklevel'] >= 1){    

        $conn->query("INSERT INTO basket(productID,username,qty) values($productID,'$username',1)");
        $conn->query("UPDATE products SET stocklevel=stocklevel-1 WHERE ID=$productID");
        echo "You have successfully added this product to your basket!";
        echo "<br><br><p> <a href='basket.php'>View my basket!</a></p>";
    }
    else{

        echo "This product is out of stock!";
        echo "<p><a href='index.php'>Back to Search page</a></p>";

    }

    //print_r($conn->errorInfo());
?>

Answer 1

可能需要更改为：SELECT stocklevel FROM products WHERE id=$productID

因为之前您从所有产品中选择了库存水平

Answer 2

您必须按产品ID

选择产品

<?php

    $productID= $_GET['ID'];
    $username = $_SESSION['solentuser']; 


    $conn=new PDO("mysql:host=localhost;dbname=user;","user","pass");

    $results=$conn->query("SELECT stocklevel FROM products Where productID=$productID");
    $row=$results->fetch();

    if($row['stocklevel'] >= 1){    

        $conn->query("INSERT INTO basket(productID,username,qty) values($productID,'$username',1)");
        $conn->query("UPDATE products SET stocklevel=stocklevel-1 WHERE ID=$productID");
        echo "You have successfully added this product to your basket!";
        echo "<br><br><p> <a href='basket.php'>View my basket!</a></p>";
    }
    else{

        echo "This product is out of stock!";
        echo "<p><a href='index.php'>Back to Search page</a></p>";

    }

    //print_r($conn->errorInfo());

仍然允许购买缺货/ php，sql

2 个答案: