title: How to get count of another table in a left join
body: <p>I have multiple tables</p>
  
  <pre><code>post
      id  Name
      1   post-name1
      2   post-name2
  
  user
      id  username
      1   user1
      2   user2
  
  post_user
      post_id   user_id
      1         1
      2         1
  
  post_comments
      post_id   comment_id
      1         1
      1         2
      1         3
  </code></pre>
  
  <p>I am using a query like this: </p>
  
  <pre><code>SELECT post.id, post.title, user.id AS uid, username
  FROM `post`
  LEFT JOIN post_user ON post.id = post_user.post_id
  LEFT JOIN user ON user.id = post_user.user_id
  ORDER BY post_date DESC
  </code></pre>
  
  <p>It works as intended. However I would like the get the number of comments for each post too. So how can I modify the this query so I can get the count of comments.</p>
  
  <p>Any ideas?</p>