title: What is rowID & rowNum (ROWID vs ROWNUM)
body: <p>I'd like to know difference between <code>rowID</code> and <code>rowNUM</code></p>
  
  <p>And how to see both of these in our table.</p>
  
  <p>when I execute this:</p>
  
  <pre><code>SELECT * FROM emp WHERE rownum=1
  </code></pre>
  
  <p>It returns one query but when I do the same for rowid it says </p>
  
  <blockquote>
    <p>inconsistent datatypes: expected ROWID got NUMBER</p>
  </blockquote>
  
  <p>And even in some of the tables, rownum returns null . Why so?</p>
  
  <p>Please clarify this: rowid vs rownum?(Demo query)</p>
  
  <p>Thank you </p>
  
  <p>EDIT: Require to use alias to display <code>ROWID</code> and <code>ROWNUM</code>(as they're pseudocolumn)
  like:</p>
  
  <p><code>SELECT rownum r1, rowid r2 FROM emp</code></p>