title: How to use PHP variables in HEREDOC SQL query?
body: <p>I am trying to perform a SQL query in PHP using HEREDOC form. While the single-line form works properly, the same kind of thing does not work in the HEREDOC form.</p>
  
  <p>This is the HEREDOC code I am attempting to use:</p>
  
  <pre><code>$sql = &lt;&lt;&lt;SQL
      SELECT *
      FROM `users`, `passwords`
      WHERE users.User_id = passwords.User_id 
      AND {$formusername} = users.User_name
      AND {$formpassword} = passwords.User_password
  SQL;
  </code></pre>
  
  <p>The above statement returns 0 rows when I know that the values I supply through my form should yield at least 1 row. Further, I know that the issue is in the AND statements because removing them yields rows. I suspect that it's the way I am writing the variables in the statement that is causing the issue.</p>
  
  <p>The below syntax works properly:</p>
  
  <pre><code>$sql = 'SELECT * FROM users, passwords WHERE users.User_id = passwords.User_id AND "'.$formusername.'" = users.User_name AND "'.$formpassword.'" = passwords.User_password';
  </code></pre>
  
  <p>1 row is correctly returned for the values I supply through the HTML5 form.</p>
  
  <p>What is wrong with my HEREDOC syntax?</p>
  
  <p>Edit: I know that I should use prepared statements to avoid SQL injection. This is just a small example for class and I need the HEREDOC form to work.</p>