title: oracle regular expression to check string contains both alphabet and number and does not contain special characters
body: <p>How to create an Oracle regular expression to check whether the given string contains both number and alphabet and does not contain special character.
  For example,</p>
  <blockquote>
  <p>if the string is like 'kjds327' it must <strong>return true</strong></p>
  <p>if the string is 'dkfsdsf' or '132564' or 'asjv@3#34342fd' it must
  <strong>return false</strong></p>
  </blockquote>