title: Add a field in a table and check condition with another column
body: <p>I need to add a field – DOC with Date type to the Registration table also ensure DOC greater than DOJ.I tried this</p>
  
  <pre><code>ALTER TABLE Registration
  ADD DOC date
  CHECK (DOC&gt;DOJ);
  </code></pre>
  
  <p>It shows error.Where i went wrong?</p>