title: mysql COUNT results with GROUP BY
body: <p>I have a table with with 2 unique linked table ids.
  I get the results I want with GROUP BY but when I count I only get the number of each group.</p>
  
  <p>When I do:</p>
  
  <pre><code>SELECT COUNT(id) FROM my_table GROUP BY first_linked_table_id, second_linked_table_id
  </code></pre>
  
  <p>I get as results 1, 2, 3, 1 but I want 4 as a result.</p>
  
  <p>I tried DISTINCT but I think that only works with one column</p>