title: What does it mean by select 1 from table?
body: <p>I have seen many queries with something as follows.</p>
  
  <pre><code>Select 1  
  From table
  </code></pre>
  
  <p>What does this <code>1</code> mean, how will it be executed and, what will it return?</p>
  
  <p>Also, in what type of scenarios, can this be used?</p>