title: Twitter-like following system
body: <p>I am working on a twitter clone in PHP for school, and I have one major problem. I cannot find a way to implement a follower system. There is a table for users, and I want to add a field that holds the ids of all of the users that each user follows.</p>
  
  <p>Should I separate the ids with commas and then split them apart in PHP? And then I need to select all of the tweets from the tweets table that were tweeted by any of the users followers. Is there an SQL command that I can use? Something similar to </p>
  
  <pre><code>SELECT *
  FROM tweets 
  WHERE author='$followeduser'"
  </code></pre>
  
  <p>but where <code>$followeduser</code> is multiple ids.</p>