title: How to pickup date from long string Name column in oracle
body: <p>I have table with column 'ID', 'File_Name'<br>
  Table    </p>
  
  <pre><code> ID     File_Name  
   123    ROSE1234_LLDAtIInstance_03012014_04292014_190038.zip   
   456    ROSE1234_LLDAtIInstance_08012014_04292014_190038.zip
  </code></pre>
  
  <p>All I need is to pickup the first date given in file name.</p>
  
  <p>Required:</p>
  
  <pre><code> ID     Date  
   123    03012014
   456    08012014
  </code></pre>