我嘗試將文件製作為html文件，或直接將<link rel="stylesheet" type="text/css" href="mystyle.css"> 立即放入，但它不起作用。
我希望能夠更改 pharagraph producten 字體大小。
這是我到目前為止的程式碼（關於最後一部分（））
<?php
include('DatabaseConnector.php');
$database = new DatabaseConnector("test", "root", "");
<link rel="stylesheet" type="text/css" href="mystyle.css">
$email = $database->selectValue("SELECT emailadres FROM klant WHERE naam = 'Bibiche' AND achternaam = 'Laarakkers'");
echo "Het emailadres van Bibiche Laarakkers is $email.";
$productInfo = $database->selectSingleRow("SELECT gewicht, prijs, calorieen FROM product WHERE naam = 'Sausage Muffin with Egg Whites'");
echo "<h2> Sausage Muffin with Egg Whites </h2>";
echo "<p>Gewicht: " . $productInfo['gewicht'] . "<br>";
echo "Prijs: " . $productInfo['prijs'] . "<br>";
echo "Aantal Calorieën: " . $productInfo['calorieen'] . "</p>";
$producten = $database->selectRows("SELECT naam, prijs FROM product");
foreach($producten as $product) {
echo "<p class='pruducten'> Product:" . $product['naam'] . "<br>";
echo "Prijs:" . $product['prijs'] . "</p>";
}
?> 
如果您嘗試在 php 程式碼中列印鏈接，您可以嘗試這樣的操作並看看它是否有效嗎？
我使用 echo 的原因是它會列印出樣式表的程式碼。如果我將程式碼直接放入 php 中間而不對其進行回顯或將其包裝在 '' 中，它將無法正確顯示或列印。
'; $email = $database->selectValue("SELECT emailadres FROM klant WHERE naam = 'Bibiche' AND achternaam = 'Laarakkers'"); echo "Het emailadres van Bibiche Laarakkers is $email."; $productInfo = $database->selectSingleRow("SELECT gewicht, prijs, calorieen FROM product WHERE naam = 'Sausage Muffin with Egg Whites'"); echo "Sausage Muffin with Egg Whites
"; echo "Gewicht: " . $productInfo['gewicht'] . "
"; $producten = $database->selectRows("SELECT naam, prijs FROM product"); foreach($producten as $product) { echo ""; echo "Prijs: " . $productInfo['prijs'] . "
"; echo "Aantal Calorieën: " . $productInfo['calorieen'] . "
Product:" . $product['naam'] . "
"; } ?>"; echo "Prijs:" . $product['prijs'] . "
如果這不起作用，因為 css 連結最好在文件的 部分中使用，您可以透過回顯程式碼將程式碼直接列印到其中，以便它正確地將其列印到頁面上。像這樣：
.pruducten { font-size:1rem; } '; $email = $database->selectValue("SELECT emailadres FROM klant WHERE naam = 'Bibiche' AND achternaam = 'Laarakkers'"); echo "Het emailadres van Bibiche Laarakkers is $email."; $productInfo = $database->selectSingleRow("SELECT gewicht, prijs, calorieen FROM product WHERE naam = 'Sausage Muffin with Egg Whites'"); echo "Sausage Muffin with Egg Whites
"; echo "Gewicht: " . $productInfo['gewicht'] . "
"; $producten = $database->selectRows("SELECT naam, prijs FROM product"); foreach($producten as $product) { echo ""; echo "Prijs: " . $productInfo['prijs'] . "
"; echo "Aantal Calorieën: " . $productInfo['calorieen'] . "
Product:" . $product['naam'] . "
"; } ?>"; echo "Prijs:" . $product['prijs'] . "
如果您絕對必須用 php 程式碼列印頁面的每個方面，以上就是我的方法。
還有其他方法可以透過直接在 php 檔案中使用 html 來實現此目的，例如確保它具有 部分等。但我想沿著您所走的道路努力，以更好地幫助您解決問題。