How can I return a pdo prepared statement to check if user exists, and then return there id from the database?
Question
I'm trying to build a method to check if a user exists, and if they do, return their id from the database. In the past I've always used mysql_fetch_array after my query, and then I would use array_shift($result_array) to obtain the id. This is proven to be a chalenge with prepared statements. Here's a look at my method:
<?php
require_once("db.php");
class User extends Database{
public $dbFields = array('username', 'password');
public $tableName = "users";
public $id;
public $username;
public $password;
// public function auth($user, $pass){
// $this->username = $user;
// $this->password = $pass;
// }
public function authenticate($username = '', $password = ''){
if(!empty($username) && !empty($password)){
$stmt = "SELECT * FROM users ";
$stmt .= "WHERE username =:username ";
$stmt .= "AND password =:password ";
$stmt = $this->db->prepare($stmt);
if($result = $stmt->execute(array(':username' => $username, ':password' => $password))){
if ($result = $stmt->fetch(PDO::FETCH_ASSOC)){
return $result;
} else {
return print("false");
}
}else{
return print("false false");
}
}
}
}
?>
This might not be relevant, but heres the form page:
if (isset($_POST['submit'])){
$username = $_POST['username'];
$password = $_POST['password'];
$user = new User();
$user->authenticate($username, $password);
}
?>
<html>
<head>
<title>test</title>
</head>
<body>
<form action = "test.php" method= "POST" accept-charset="utf-8" >
<p>Username
<input type="text" name="username" maxlength="30" value="" />
</p>
<p>Password
<input type="password" name="password" maxlength="30" value="" />
</p>
<p><input type="submit" name="submit" value="Continue →"></p>
</form>
</body>
</html>
I've been using pdo successfully on all of my other db methods so I really don't want to switch back to a standard mysql statement if I can help it. Any advice?
Edit: changed syntax in execute array as advised by Chris.
2 answers
solution1
1 ACCPTED 2011-12-05 21:33:16
php doesnt expand variables in strings delimited by single quotes.
use something like
array(':username' => $username, ':password' => $password)
Aside from that, your variable $result is an associative array just like you're used to.
return $result['id'];
note, the print function returns the value of 1. I really don't think you want to be returning this value from your authenticate function. How will you tell if the 1 is someones user id, or if its the return value of print? return boolean false instead to indicate failure.
solution2
0 2011-12-05 17:53:10
You want an output variable in your prepared statement. The syntax is generally:
Create Procedure PROCEDURE NAME (OUTPUTVARNAME DBTYPE out)
but its going to vary between database implementations. Try: http://www.php.net/manual/en/book.pdo.php#68398
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