What is the equivalent of bind_result on PDO

Question

I\'m converting to PDO and Im using prepared statements, I want to bind my result as so $stmt->bind_result($email_count); so i am able to put this into an if

Answer 1

For quickly retrieving a value from something like a SELECT COUNT() query, have a look at PDOStatement::fetchColumn, eg

$stmt = $pdo->prepare('SELECT COUNT(1) FROM users WHERE email = :email');
$stmt->bindParam(':email', $email);
$stmt->execute();
$email_count = $stmt->fetchColumn();

I'd also like to offer some further advice. You shouldn't be creating a PDO connection in your class constructor. This means that every time you instantiate a class extending Database, you create a new connection. Instead, pass the PDO instance as a dependency, eg

abstract class Database {
    /**
     * @var PDO
     */
    protected $pdo;

    public function __construct(PDO $pdo) {
        $this->pdo = $pdo;
    }
}

The same goes for your User::insert method. Try to pass any required parameters via method arguments. If you ever want to start writing unit tests for your classes, this will be invaluable

public function insert($email) {
    $stmt = $this->pdo->prepare('SELECT COUNT(1) FROM users WHERE email = :email');
    $stmt->bindParam(':email', $email);
    $stmt->execute();
    $email_count = $stmt->fetchColumn();

    // and so on

And finally, for PHP only files, omit the closing PHP tag ?>. This will save you from accidentally including whitespace at the end of your files that may be sent to the browser.