title: "subquery returns more than 1 row" error.
body: <p>I am new to web programming and I'm trying to make a twitter-clone.  At this point, I have 3 tables:</p>
  
  <blockquote>
    <p>users (id, name)</p>
  </blockquote>
  
  <ul>
  <li>id is the auto-generated id  </li>
  <li>name of the user</li>
  </ul>
  
  <blockquote>
    <p>tweets (id, content, user_id)</p>
  </blockquote>
  
  <ul>
  <li>id is the auto-generated id</li>
  <li>content is the text of the tweet</li>
  <li>user_id is the id of the user that made the post</li>
  </ul>
  
  <blockquote>
    <p>followers (id, user_id, following_id)</p>
  </blockquote>
  
  <ul>
  <li>id is the auto-generated id</li>
  <li>user_id is the user who is doing the following</li>
  <li>following_id is the user that is being followed</li>
  </ul>
  
  <p>So, being new to sql as well, I am trying to build an SQL statement that would return the tweets that the currently-logged in user and of everyone he follows.</p>
  
  <p>I tried to use this statement, which works sometimes, but other times, I get an error that says "Subquery returns more than 1 row".  Here is the statement:</p>
  
  <pre><code>SELECT * FROM tweets 
  WHERE user_id IN
  ((SELECT following_id FROM followers
  WHERE user_id = 1),1) ORDER BY date DESC
  </code></pre>
  
  <ul>
  <li>I put 1 as an example here, which would be the id of the currently logged-in user.</li>
  </ul>
  
  <p>I haven't had any luck with this statement; any help would be greatly appreciated!  Thank you.</p>