title: oracle REGEXP .* understanding concern
body: <p>Question- select all city from station table where start and end letter of city must be any vowel (a/e/i/o/u).</p>
  <p>The solution which I through:
  `` SELECT city FROM station WHERE REGEXP_LIKE (city, '^(a|e|i|o|u)$', 'i')```</p>
  <p>But this is not Giving any output, I searched for the solution online and here is the working code:
  `` SELECT city FROM station WHERE REGEXP_LIKE (city, '^(a|e|i|o|u).*(a|e|i|o|u)$', 'i')```</p>
  <p>I tried to search online but didn't understood why applying <strong>.</strong>* in between worked.  For my code I think its not working as I am using same sub expression for start(^) and end($).</p>
  <p>Can anyone please help me understand the <strong>.</strong>* working here.</p>