title: SQL union but vertically
body: <p>recently started with simple queries in SQL</p>
  
  <p>I was wondering if there is a possibility to add data vertically like "union" does horizontally</p>
  
  <p>I have two selection i want to combine</p>
  
  <pre><code>month year data1 data2 grouped by month, year
  month year data3 data4 grouped by month, year
  </code></pre>
  
  <p>what I'm trying to archive is </p>
  
  <pre><code>month year data1 data2 data3 data4
  </code></pre>
  
  <p>Is there any function working like union to archive this? I was trying to do so with "join" but failed horribly</p>