查询和获取比较SQLite

I'm just creating a simple login script to check the username/password, if there's a match with the database then it'll login. I think I have most of it, it opens up the database, grabs username/pw from the login. I think I set up my query right also that it grabs the username and pw. How would I go about comparing it? I've been stuck on this for quite a while. My fetch isn't working correctly also, it gives me an error. I'm very new to SQLite/Databases so this may seem very bad code but I'm trying my best.

<?php

//opens database
   class MyDB extends SQLite3
   {
      function __construct()
      {
         $this->open('UserAccounts.db');
      }
   }
   $db = new MyDB();

   //username and pw from index.html
   $user = $_REQUEST['myusername'] ; 
   $pw = $_REQUEST['mypassword'] ;

   //if there is a database, it opens.
   if(!$db){
      echo $db->lastErrorMsg();
   } else {
      //Test to see if things are working correctly.
      echo "Opened database successfully
";
      echo "$user";
      echo "$pw";

   }
   $result = $db->query("SELECT * FROM login WHERE user = '$user' AND password = '$pw'");
   if ($result->fetchColumn() == $user) {
     $_SESSION['loggedin'] = true;
     echo "Success";
   };

   if(!$_SESSION['loggedin']){
      echo "Didn't Work";
      exit;
   };

Probably looks like this:

$fromDB = $result->fetchArray();
if ($fromDB['user'] == $user) {