title: Nested Select in From Clause
body: <p>In SQL Server,</p>
  
  <p>you can write nested SQL like this:</p>
  
  <pre><code>SELECT T.con
  FROM (SELECT count(*) as "con" FROM EMP) AS T
  </code></pre>
  
  <p>In such way, I can get a temp table T that can be nested into other query.</p>
  
  <p>But I cannot do the same thing in oracle SQL</p>
  
  <p>It gives me <code>ORA-01747:invalid column</code></p>
  
  <pre><code>SELECT *
  FROM (SELECT count(*) as "con" FROM EMP) T
  </code></pre>
  
  <p>select * works, but it's not what I want. Anybody knows how to do it?</p>