MySQL - SUM DateTime?
<p>I need sum datetime values, but I don't know how I can do this.</p>

<p>I've the table:</p>

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

<p>And my query:</p>

<pre><code>SELECT 
    SUM(h.dtplay) AS Time 
FROM 
    tblhistory AS h, 
    tblgame AS g 
WHERE 
    h.idgame = g.id AND 
    g.description = gameName;
</code></pre>

<p>But, when I run that query, my result is:</p>

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

<p>Why it's incorrect?</p>

<p><strong>EDIT</strong></p>

<p>I change the format from datetime to time in my table:</p>

<p><a href="https://i.stack.imgur.com/H8L6y.png" rel="noreferrer"><img src="https://i.stack.imgur.com/H8L6y.png" alt="enter image description here"></a></p>

<p>So, I need sum the time values.</p>

<p><strong>EDIT 2</strong></p>

<p>The correct query:</p>

<pre><code>SELECT 
   SEC_TO_TIME(SUM(TIME_TO_SEC(h.DtPlay))) AS Time 
FROM 
   tblhistory AS h, 
   tblgame AS g 
WHERE 
   h.idgame = g.id AND 
   g.description = gameName;
</code></pre>

<p>Thanks for @Newbee Dev and @EhsanT  :)</p>