Select 2 columns with PHP PDO Query - php

Question

I'm pretty new to PHP and PDO and I'm trying to make a simple login system. Now, I'm trying to fetch the id and password from my table to compare with the password that the user input(I'm using one way encryption with salt). So, now the problem is, when I do $password = $stmt->fetchColumn(1) only, my login system works. Now when I try to get the id by doing $id = $stmt->fetchColumn(0) just before $password, I cannot login anymore and I get my "Wrong Username/Password" error.
Now I'm pretty sure that I'm doing something wrong with the fetchColumn but I can't figure it out.
Here's a code snippet that works:
$con = new PDO( DB_DSN, DB_USERNAME, DB_PASSWORD );
//set how pdo will handle errors
$con->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
//this would be our query.
$sql = "SELECT id, password FROM user_admin WHERE email = :email";
//prepare the statements
$stmt = $con->prepare( $sql );
//give value to named parameter :email
$stmt->bindValue( "email", $this->email, PDO::PARAM_STR );
$stmt->execute();
$password = $stmt->fetchColumn(1);
Now the following doesn't work. Notice that this happens when I added the $id:
$con = new PDO( DB_DSN, DB_USERNAME, DB_PASSWORD );
//set how pdo will handle errors
$con->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
//this would be our query.
$sql = "SELECT id, password FROM user_admin WHERE email = :email";
//prepare the statements
$stmt = $con->prepare( $sql );
//give value to named parameter :email
$stmt->bindValue( "email", $this->email, PDO::PARAM_STR );
$stmt->execute();
$id = $stmt->fetchColumn(0); //That's the problem
$password = $stmt->fetchColumn(1);
Any help is greatly appreciated.

Answer 1

From the documentation:
PDOStatement::fetchColumn — Returns a single column from the next row of a result set
Each time you call fetchColumn it advances to the next row of the result set.
Try using PDOStatement::fetch instead to fetch the entire row as an an array and then accessing the values from there.
$stmt->execute();
$row = $stmt->fetch();
$id = $row[0];
$password = $row[1];