title: SQL - Define a column and use it in the same query
body: <p>Can I define a new column and use it in the same query? </p>
  
  <p>For example,</p>
  
  <pre><code>Select 
      student, age + 10 as trueage, 
      case when trueage &lt; 25 then 'False' else 'True' end
  From 
      class
  </code></pre>
  
  <p>Thank you in advance for helping!</p>