来自Web表单问题的PHP准备语句[重复]

Question

这个问题在这里已有答案：

Apache shows php code instead of executing 20个答案

直到最近才开始使用mysql所以我正在慢慢掌握它，但是尝试使用php预处理语句进行webform，并且在提交webform时，它只是显示php代码。有什么建议？

谢谢

<?php

$link = mysqli_connect("localhost", "root", "", "contactform");

if($link === false){
die("ERROR: Could not connect. " . mysqli_connect_error());
}

$sql = "INSERT INTO contactform (firstname, surname, address1, address2, 
towncity, county, postcode) VALUES (?,?,?,?,?,?,?)";

if($stmt = mysqli_prepare($link, $sql)){
mysqli_stmt_bind_param($stmt, "sssssss", $firstname, $surname, $address1, 
$address2, $towncity, $county, $postcode);

$firstname = $_REQUEST['firstname'];
$surname = $_REQUEST['surname'];
$address1 = $_REQUEST['address1'];
$address2 = $_REQUEST['address2'];
$towncity = $_REQUEST['towncity'];
$county = $_REQUEST['county'];
$postcode = $_REQUEST['postcode'];


if(mysqli_stmt_execute($stmt)){
    echo "Records inserted successfully.";
} else{
    echo "ERROR: Could not execute query: $sql. " . mysqli_error($link);
}
} else{
echo "ERROR: Could not prepare query: $sql. " . mysqli_error($link);
}

mysqli_stmt_close($stmt);

mysqli_close($link);
?>