title: Sum values from different table using LEFT JOIN
body: <p>I'm trying to sum all <code>coins</code> from <code>m_z_analytics</code> when <code>site</code> have number same as <code>id</code> from <code>m_b_browsing_live</code> (see result below).</p>
  
  <p>Tables:</p>
  
  <pre><code>m_z_analytics
  
  id|site_id|coins|
   1|      1| 0.01|
   2|      2|  0.1|
   3|      1| 0.08|
   4|      2|  0.1|
   3|      3|  0.2|
  
  
  m_b_browsing_live
  
  id| cpc|
   1|0.09|
   2| 0.1|
   3| 0.5|
  </code></pre>
  
  <p>The final result should be: <strong>0.38</strong> 
  <em>(0.09 + 0.1 + 0.09 + 0.1)</em></p>
  
  <p>I've tried so far:</p>
  
  <pre><code>SELECT SUM(a.coins) AS money FROM m_z_analytics a
  LEFT JOIN m_b_browsing_live b ON b.id=a.site_id
  WHERE CONCAT(',', `a.site_id`, ',') REGEXP ',(1|2),'
  </code></pre>