从 MySQL 转换后 PDO 脚本不工作

Posted 2023-02-24

【中文标题】从 MySQL 转换后 PDO 脚本不工作

【英文标题】：PDO Script Not Working After Converting from MySQL

【发布时间】：2015-01-22 21:55:24

【问题描述】：

提前感谢您的帮助。我在第一部分有一个带有 AJAX 电子邮件收集表单的登录页面，我改编自 Tutsplus tutorial。

但是，表单的 php 部分是用 mysql 编写的，它与我的 Heroku 服务器不兼容，因为它已被弃用。在 *** 上听取其他人的建议，我尝试将代码中的 MySQL 语句转换为 PDO。但是很难让表单正常工作。

这是原始的工作 MySQL 代码

<?php
if($_GET['action'] == 'signup')
// if(isset($_GET['action'])&& $_GET['action'] == 'signup')

	mysql_connect('hostname','username','password');
	mysql_select_db('databasename');

	$email = mysql_real_escape_string($_POST['emailfield']);

	//validate email address - check if input was empty
	if(empty($email))
		$status = "error";
		$message = "You did not enter an email address!";
	
	else if(!filter_var($email, FILTER_VALIDATE_EMAIL)) //validate email address - check if is a valid email address
			$status = "error";
			$message = "You have entered an invalid email address!";
	
	else 
		$existingSignup = mysql_query("SELECT * FROM table WHERE signup_email_address='$email'");   
		if(mysql_num_rows($existingSignup) < 1)

			date_default_timezone_set('Asia/Singapore');
			$date = date('Y-m-d');
			$time = date('H:i:s');
			
			$insertSignup = mysql_query("INSERT INTO table (signup_email_address, signup_date, signup_time) VALUES ('$email','$date','$time')");
			if($insertSignup) //if insert is successful
				$status = "success";
				$message = "You have been signed up!";	
			
			else  //if insert fails
				$status = "error";
				$message = "Oops, Theres been a technical error!";	
			
		
		else  //if already signed up
			$status = "error";
			$message = "This email address has already been registered!";
		
	
	
	//return json response
	$data = array(
		'status' => $status,
		'message' => $message
	);

	echo json_encode($data);
	exit;

?>

这是我将上述 MySQL 代码转换为 PDO 的失败尝试

<?php
if(isset($_GET['action'])&& $_GET['action'] == 'signup')

	try 
		$db = new PDO('mysql:host=hostname;dbname=dbname;charset=utf8','user','pwd');
	
	catch(exception $e) 
		echo "Error, connection failure";
	

	$email = $_POST['emailfield'];

	//validate email address - check if input was empty
	if(empty($email))
		$status = "error";
		$message = "You did not enter an email address!";
	
	else if(!filter_var($email, FILTER_VALIDATE_EMAIL)) //validate email address - check if is a valid email address
			$status = "error";
			$message = "You have entered an invalid email address!";
	
	else 

		$existingSignup = "SELECT COUNT(*) FROM table WHERE signup_email_address='$email'";
		if ($res->fetchColumn() < 1) 

			date_default_timezone_set('Asia/Singapore');
			$date = date('Y-m-d');
			$time = date('H:i:s');
			
			$insertSignup = "INSERT INTO table (signup_email_address, signup_date, signup_time) VALUES (:signupemail, :signupdate, :signuptime)";

		    $query = $db->prepare($insertSignup);
		    $query->bindParam(':signupemail', $email);
		    $query->bindParam(':signupdate', $date);
		    $query->bindParam(':signuptime', $time);
		    $results = $query->execute();

			if($insertSignup) //if insert is successful
				$status = "success";
				$message = "You have been signed up!";	
			
			else  //if insert fails
				$status = "error";
				$message = "Oops, Theres been a technical error!";	
			
		
		else  //if already signed up
			$status = "error";
			$message = "This email address has already been registered!";
		
	
	
	//return json response
	$data = array(
		'status' => $status,
		'message' => $message
	);

	echo json_encode($data);
	exit;

?>

您能给我建议以更正我的 PDO 代码吗？谢谢！

更新：

这是我更新的 PDO 代码：

<?php
if(isset($_GET['action'])&& $_GET['action'] == 'signup')

	try 
		$db = new PDO('mysql:host=hostname;dbname=dbname;charset=utf8','user','pwd');
		$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
		error_reporting(-1);
	
	catch(PDOexception $e) 
		echo "Error, connection failure";
	

	$email = $_POST['emailfield'];

	//validate email address - check if input was empty
	if(empty($email))
		$status = "error";
		$message = "You did not enter an email address!";
	
	else if(!filter_var($email, FILTER_VALIDATE_EMAIL)) //validate email address - check if is a valid email address
			$status = "error";
			$message = "You have entered an invalid email address!";
	
	else 
			$existingSignup = "SELECT * FROM table WHERE signup_email_address='$email'";
			$stmt = $db->query($existingSignup);
			$row_count = $stmt->rowCount();
			if ($row_count < 1) 

			date_default_timezone_set('Asia/Singapore');
			$date = date('Y-m-d');
			$time = date('H:i:s');
			
			$insertSignup = "INSERT INTO table (signup_email_address, signup_date, signup_time) VALUES (:signupemail, :signupdate, :signuptime)";

		    $query = $db->prepare($insertSignup);
		    $query->bindValue(':signupemail', $email);
		    $query->bindValue(':signupdate', $date);
		    $query->bindValue(':signuptime', $time);
		    $results = $query->execute();

			if($insertSignup) //if insert is successful
				$status = "success";
				$message = "You have been signed up!";	
			
			else  //if insert fails
				$status = "error";
				$message = "Oops, Theres been a technical error!";	
			
		
		else  //if already signed up
			$status = "error";
			$message = "This email address has already been registered!";
		
	
	
	//return json response
	$data = array(
		'status' => $status,
		'message' => $message
	);

	echo json_encode($data);
	exit;

?>

但这是我得到的错误：致命错误：在第 27 行对 index.php 中的非对象调用成员函数 query()。

第 27 行：

$stmt = $db->query($existingSignup);

我该如何解决这个问题？

【问题讨论】：

我不确定，但可能会抛出非对象错误，因为您的 DVD 连接不好。所以我建议验证 PDO 类的参数（即 dbname、用户名、密码和主机名）

看看这个问题：***.com/questions/15297339/…。我在之前的评论中有一个错字我指的是变量 $db 而不是 DVD .. 哈哈

谢谢哥们，在你的帮助下我搞定了！

【参考方案1】：

您的$existingSignup 查询未执行。你必须使用类似的东西：

$stmt = $db->query($existingSignup);
$row_count = $stmt->rowCount();
echo $row_count.' rows selected

然后继续：if ($row_count < 1) ...

了解更多信息。查阅此链接：http://wiki.hashphp.org/PDO_Tutorial_for_MySQL_Developers