我正在用PHP/MySQL写简单的博客，我在数据库中插入一些数据时遇到了问题。我正在尝试添加评论总是收到错误 - 未添加评论。我无法弄清楚代码出了什么问题。有人能帮忙吗？
<?php
if(!isset($_GET['id'])) {
header('Location: index.php');
exit();
} else {
$id = $_GET['id'];
}
if(!is_numeric($id)) {
header('Location: index.php');
}
// Include database connection
include('includes/db_connect.php');
$sql = "SELECT post_title, post_body FROM posts WHERE post_id='$id'";
$query = $db->query($sql);
//echo $query->num_rows;
if($query->num_rows != 1) {
header('Location: index.php');
exit();
}
if(isset($_POST['submit-comment'])) {
$email = $_POST['email'];
$name = $_POST['name'];
$comment = $_POST['comment'];
$email = $db->real_escape_string($email);
$name = $db->real_escape_string($name);
$comment = $db->real_escape_string($comment);
$id = $db->real_escape_string($id);
if($email && $name && $comment) {
$sqlComment = "INSERT INTO comments (post_id, email, name, comment) VALUES ('$id','$email','$name','$comment')";
$queryComment = $db->query($sqlComment);
if($queryComment) {
echo "Comment was added";
} else {
echo "Comment not added";
}
} else {
echo "Error";
}
}
?>
<! DOCTYPE html >
<!--[if lt IE 7]> <html class="lt-ie9 lt-ie8 lt-ie7"> <![endif]-->
<!--[if IE 7]> <html class="lt-ie9 lt-ie8"> <![endif]-->
<!--[if IE 8]> <html class="lt-ie9"> <![endif]-->
<!--[if gt IE 8]><!--><html class=""><!--<![endif]-->
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Blog System</title>
<link rel="stylesheet" href="css/application.css" type="text/css">
<style type="text/css">
label {
display: block;
}
</style>
</head>
<body>
<div id="container">
<div id="post">
<?php
$row = $query->fetch_object();
echo "<h2>" . $row->post_title . "</h2>";
echo "<p>" . $row->post_body . "</p>";
?>
</div>
<hr>
<div id="add-comments">
<form action="<?php echo $_SERVER['PHP_SELF'] . '?id=' . $id ?>" method="post">
<label for="email">Email Address:</label>
<input type="text" name="email" id="email"><br>
<label for="name">Name:</label>
<input type="text" name="name" id="name"><br>
<label for="comment">Comment</label>
<textarea name="comment" id="comment" cols="30" rows="10"></textarea><br>
<br><br>
<input type="submit" name="submit-comment" value="Post your comment" id="postyourcomment">
</form>
</div>
</div>
<script type="text/javascript" src="js/application.min.js"></script>
</body>
</html>
<?php
if(isset($_POST['submit-comment'])) {
if(!isset($_GET['id'])) {
header('Location: index.php');
exit();
} else {
$id = $_GET['id'];
}
if(!is_numeric($id)) {
header('Location: index.php');
}
// Include database connection
include('db_connect.php');
$sql = "SELECT post_title, post_body FROM posts WHERE post_id=".$id." ";
$query = $db->query($sql);
//echo $query->num_rows;
if($query->num_rows != 1) {
header('Location: index.php');
exit();
}
$email = $_POST['email'];
$name = $_POST['name'];
$comment = $_POST['comment'];
$email = $db->real_escape_string($email);
$name = $db->real_escape_string($name);
$comment = $db->real_escape_string($comment);
$id = $db->real_escape_string($id);
if($email && $name && $comment) {
$sqlComment = "INSERT INTO comments (post_id, email, name, comment) VALUES (".$id.",'".$email."','".$name."','".$comment."')";
$queryComment = $db->query($sqlComment);
if($queryComment) {
echo "Comment was added";
} else {
echo "Comment not added";
}
} else {
echo "Error";
}
}
?>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Blog System</title>
<link rel="stylesheet" href="file:///C|/Users/Jaydeep Jivani/Desktop/css/application.css" type="text/css">
<style type="text/css">
label {
display: block;
}
</style>
</head>
<body>
<div id="container">
<div id="post">
<?php
$row = $query->fetch_object();
echo "<h2>" . $row->post_title . "</h2>";
echo "<p>" . $row->post_body . "</p>";
?>
</div>
<hr>
<div id="add-comments">
<form action=<?=$_SERVER['PHP_SELF']?> method="get">
<input type="hidden" name="id" value=<?=$id?> />
<label for="email">Email Address:</label>
<input type="text" name="email" id="email"><br>
<label for="name">Name:</label>
<input type="text" name="name" id="name"><br>
<label for="comment">Comment</label>
<textarea name="comment" id="comment" cols="30" rows="10"></textarea><br>
<br><br>
<input type="submit" name="submit-comment" value="Post your comment" id="postyourcomment">
</form>
</div>
</div>
<script type="text/javascript" src="file:///C|/Users/Jaydeep Jivani/Desktop/js/application.min.js"></script>
</body>
</html>
谢谢大家的帮助。我发现了一个与我的数据库有关的问题，不幸的是我用comment_id构建了表格，忘记添加AI属性。
多亏了@tadman我才能重写我的代码，这是最终的工作结果：
if(isset($_POST['submit-comment'])) {
$email = $_POST['email'];
$name = $_POST['name'];
$comment = $_POST['comment'];
$email = $db->real_escape_string($email);
$name = $db->real_escape_string($name);
$comment = $db->real_escape_string($comment);
$id = $db->real_escape_string($id);
if($email && $name && $comment) {
// Prepare statemnt
$sqlComment = "INSERT INTO comments (post_id, email, name, comment) VALUES (?, ?, ?, ?)";
$queryComment = $db->prepare($sqlComment);
$queryComment->bind_param('ssss', $id, $email, $name, $comment);
// Execute prepared statement
$queryComment->execute();
if($queryComment) {
echo "Comment was added.";
} else {
echo "There was a problem. Error: " . mysqli_error($db);
}
// Close statement
$queryComment->close();
} else {
echo "Error";
}