title: PHP Mysql query is returning null
body: <p>I have a simple PHP login function. Within this function, I am checking to see if the user exist by making a MySQL query that is selecting username from a table and counting the number of rows that is returned. I am having trouble with the query returning null when I know for a fact that the table contains the username. <br/><br/></p>
  
  <p>Here is my code.<br/></p>
  
  <pre><code>function login($user_name, $password) {
      $db1 = new DB_CONNECT();        
      $db1-&gt;connect();
  
      $query = "SELECT user_name FROM users WHERE user_name = '$user_name'";
      $result = $db1-&gt;makeAQuery($query);
  
      if (mysql_num_rows($result) == 1) {
          //check the password
      }
      else {
          //no user exist 
      }
  }
  </code></pre>
  
  <p><br/>
  I know that the username and password that are coming in are OK and I trim for any white spaces before I sent them to the function. I know that the database connection is working because it works on the rest of my PHP code. The only error that I am getting is one that mentions that the mysql_num_rows "expects parameter 1 to be resource, null given" 
  <br/><br/></p>
  
  <p>Database class</p>
  
  <pre><code>class DB_CONNECT {
      function connect() {
          // import database connection variables
          require_once __DIR__ . '/db_config.php';
          $con = mysql_connect(DB_SERVER, DB_USER, DB_PASSWORD) or die(mysql_error());
  
          // Selecing database
          mysql_select_db(DB_DATABASE, $con) or die(mysql_error());
      }
      function makeAQuery($query) {
          $result = mysql_query($query) or die(mysql_error());        
      } 
      function close() {
         // closing db connection
      mysql_close();
      }
  }
  </code></pre>