title: Build a regexp for Oracle where last 4 values are 0-9 1-Z and not G I O S alphabets
body: <p>The requirement to generate a Client id is <code>D&lt;ABCDEFHJKL&gt;XXXX</code> - Where <code>X</code> can be <code>0-9</code>, <code>A-Z</code> but not the letters <code>G</code>,<code>I</code>,<code>O</code>, or <code>S</code>.</p>
  
  <p>I have created a regular expression which is generating a Client Id to be used in the database.</p>
  
  <p>The regular expression is as follows.
  <code>D[A-FHJ-L]{1}[^_:?GIOS-]{4}</code></p>
  
  <p>However, I am not sure how to enhance it that in the last 4 'X', it limits them with <code>0-9</code>, <code>A-Z</code> and not <code>G</code>, <code>I</code>, <code>O</code>, or <code>S</code>.</p>
  
  <p>e.g. It will match <code>DAaaa_</code> or <code>DL00gA</code> and I want to exclude those.</p>
  
  <p>Please suggest a better approach or a possible solution.</p>
  
  <p>Thanks</p>