Query in Access 2010
<p>With this query </p>

<pre><code>SELECT Year, Month,  Customer, Cod_user, Int(Sum(hours)) AS hours
FROM T_Att
GROUP BY Year, Mounth, Customer, Cod_user
HAVING (((Year)="2016") AND ((Month)="03") AND ((Customer)="CA"));
</code></pre>

<p>I get the following result</p>

<p><a href="https://i.stack.imgur.com/4TZ10.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/4TZ10.jpg" alt="enter image description here"></a></p>

<p>If you want to add the <strong>global sum (sum)</strong> and a <strong>key</strong>, what needs to change?</p>

<p><a href="https://i.stack.imgur.com/upufW.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/upufW.jpg" alt="enter image description here"></a></p>