Question

I am trying to match a username in the database. If the username match it returns true otherwise it returns false.

At the moment it will always return false even when the username is correct.

Here is the class and call I’m using:

class register{
  private $result;

  public function __construct($post_data, PDO $dbh){

    $this->post_data = array_map('trim', $post_data);
    $this->dbh = $dbh;

  }

  public function checkUsername(){
    $stmt = $this->dbh->prepare("COUNT(*) FROM oopforum_users WHERE username = ?");
    $stmt->bindParam(1, $this->post_data['reg_username'], PDO::PARAM_STR);
    $stmt->execute();
    $this->result = $stmt->rowCount();
    if($this->result == 0){
        return false;
    }else{
        return true;
    }
  }

}


$register = new register($_POST, $dbh);
if($register->checkUsername()){
    //continue
}else{
    echo 'ERROR: That username is taken, please choose another one.';
}

Why is it returning false even though the username’s do match?

Answer 1

You forgot the SELECT statement:

$stmt = $this->dbh->prepare("SELECT COUNT(*) FROM oopforum_users WHERE username = ?");

Apart from that your query will always return a row (exactly 1 row), but the contents of that row could contain a 0 for the row count, so you need to change your logic: Either select a real column instead of COUNT(*) and use $stmt->rowCount() or read the value of the count and check for that.