title: SQL JOIN query writing
body: <p>I'm trying to write a simple query involving two tables.  The "person" table has a unique <code>person_id</code> and a <code>name</code>, and the "friends" table has a <code>person_id</code> and a <code>friend_id</code> which is a FK to a <code>person_id</code> in the person table.</p>
  
  <pre><code>person:
  &lt;PK&gt; int person_id 
  varchar[45] name
  
  friends: 
  &lt;PK&gt; int person_id
  &lt;PK&gt; int friend_id
  </code></pre>
  
  <p>I want to select the name of all of person 1's friends.</p>
  
  <p>I can do this easily using an <code>IN</code> statement:</p>
  
  <pre><code>SELECT p.name FROM person p WHERE p.person_id IN (SELECT f.friend_id FROM friends f WHERE f.person_id = 1);
  </code></pre>
  
  <p>However, I am not proficient at writing <code>JOIN</code> statements.  Can somebody help me write the equivalent join?</p>
  
  <p>Clearly this is a contrived example, but I have tried with my real data and am conceptually missing something.  Thanks.</p>