title: Adding A Column that doesn't exist in a query
body: <p>I want to add a column in a query that does not exist in a table and return it as a result. So lets say TABLE_TEST has column A, B and I want to return values for A, B and C. I am trying to do</p>
  
  <pre><code>SELECT A, B, C=3 FROM TABLE_TEST
  </code></pre>
  
  <p>or</p>
  
  <pre><code>SELECT *, C=3 FROM TABLE_TEST
  </code></pre>
  
  <p>Can this be done in MySQL, Postgresel or MSSQL?</p>