title: How to merge zero values (vector(0) with metric values in PromQL
body: <p>I'm using <a href="https://github.com/mjtrangoni/flexlm_exporter" rel="noreferrer">flexlm_exporter</a> to export my license usage to Prometheus and from Prometheus to custom service (Not Graphana).</p>
  <p>As you know Prometheus hides missing values.</p>
  <p>However, I need those missing values in my metric values, therefore I added to my prom query <code>or vector(0)</code></p>
  <p>For example:</p>
  <pre><code>flexlm_feature_used_users{app=&quot;vendor_lic-server01&quot;,name=&quot;Temp&quot;} or vector(0)
  </code></pre>
  <p>This query adds a empty metric with zero values.</p>
  <p>My question is if there's a way to merge the zero vector with each metric values?</p>
  <p>Edit:</p>
  <p>I need grouping, at least for a user and name labels, so vector(0) is probably not the best option here?
  <a href="https://i.stack.imgur.com/1ek4L.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/1ek4L.jpg" alt="Example query with a specific user with missing values and zero vector" /></a></p>
  <p>I tried multiple solutions in different StackOverflow threads, however, nothing works.</p>
  <p>Please assist.</p>