php - 如果价格已降低，则从 mySQL 数据库获取一行

Question

这个问题已经有答案了:

When to use single quotes, double quotes, and backticks in MySQL (13 个回答)

已关闭 7 年前。

我试图仅显示数据库中已减少设置为"is"的产品，但收到以下错误:Warning: Invalid argument supplied for foreach() in /reduced.php on line 79

减少.php

<?php
                $pdo = new PDO('mysql:host=localhost;dbname','name','password');
                $reduced = 'yes';
                $result = $pdo->query('SELECT file_id, productName, price, stock, reduced FROM files WHERE reduced = '.$reduced.'');
                foreach($result as $row){
                    echo "<div id='shop'>";
                    echo "<img id='product' src=\"file.php?id={$row['file_id']}\">";
                    echo '<p>' . $row['productName'] . '</p>';
                    echo '<p>' . "£" . $row['price'] . '</p>';
                    echo '<p>' . "Stock Level: " . $row['stock'] . '</p>';
                    echo '<a href="basket.php">ADD TO BASKET</a>';
                    echo "</div>";
                }
            ?>

Answer 1

这是引号尝试

 $result = $pdo->query('SELECT file_id, productName, price, stock, reduced FROM files WHERE reduced = "'.$reduced.'"');