title: 2 SELECT in 1 query results in 4 results when expecting 2 results
body: <p>I have 2 tables in mysql database: accounts and users</p>
  
  <p>Accounts looks like this:<a href="https://i.stack.imgur.com/jAiXw.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jAiXw.png" alt="enter image description here"></a></p>
  
  <p>Users Looks like this:<a href="https://i.stack.imgur.com/CO0nH.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/CO0nH.png" alt="enter image description here"></a></p>
  
  <p>I want to select accountid and userid from both tables and get results like so:</p>
  
  <pre><code>accountid || userid
  7            22
  29           44     
  </code></pre>
  
  <p>I don't understand why it gives me 4 results like so:</p>
  
  <p><a href="https://i.stack.imgur.com/pSKRX.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/pSKRX.png" alt="enter image description here"></a></p>