title: JPA - Only select object for first day of month
body: <p>I am collecting daily datasets like this:</p>
  
  <pre><code>date        value
  01.01.2017  5
  02.01.2017  6
  03.01.2017  10
  .
  .
  .
  01.02.2017  30
  02.02.2017  33
  .
  .
  .
  01.03.2017  50
  </code></pre>
  
  <p>So one entry per day. Then I use this to draw some chart. Now if the data gets to much, I want to draw a monthly chart instead and therefore only select the first object for the month. E.g. the result should be:</p>
  
  <pre><code>date        value
  01.01.2017  5
  01.02.2017  30
  01.03.2017  50
  </code></pre>
  
  <p>Is there a way to get this result with JPQL? The result should be contain entity objects.</p>