此PDO语句返回整数而不是字符串

Question

In a class, I have some PDO:

$userFName = 'userFName';
include('dbconnect.php');       // Normally I'd store the db connect script outside of webroot
$pdo = new PDO("mysql:host=$db_host;dbname=$db_name;", $db_user, $db_password);
$stmt = $pdo->prepare('SELECT userFName FROM Users WHERE username = :uname AND password = :pword AND roleID = 1');
$stmt->bindParam(':uname', $this->user->username);
$stmt->bindParam(':pword', $this->user->password);
$stmt->bindColumn(4, $userFName, PDO::PARAM_STR);
$stmt->execute();
$familiar = $stmt->fetch(PDO::FETCH_BOUND);
$this->user->firstName = $familiar;

It's returning the ID in the first column instead of the VARCHAR contents in the 4th column. Any idea why?

Answer 1

When using PDO::FETCH_BOUND with fetch(), the method will not return a result record. Instead the value of the column should be available in the variable you have bound using $stmt->bindColumn() earlier.

So change your code to:

$stmt->bindColumn(1, $userFName, PDO::PARAM_STR);
$stmt->execute();
$stmt->fetch(PDO::FETCH_BOUND);
$this->user->firstName = $userFName; // <-- use the bound variable

---

However you won't need that bindColumn() call. You could simplify the code as this:

$stmt->execute();
$row = $stmt->fetch(); // uses PDO::FETCH_ASSOC by default
$this->user->firstName = $row['FName'];