title: Generate Upper and Lowercase Alphanumeric Random String in Oracle
body: <p>How does one generate an upper and lowercase alphanumeric random string from oracle?</p>
  
  <p>I have used <code>select DBMS_RANDOM.STRING('x', 10) from dual</code> to generate uppercase alphanumeric characters</p>
  
  <p>and <code>select DBMS_RANDOM.STRING('a', 10) from dual</code> to generate uppercase and lowercase alpha characters</p>
  
  <p>...but I'd like a function that does both upper and lower case, and alpha and numeric characters.</p>
  
  <p>Also, bonus points (or just upvotes) if you can think of good reasons why Oracle didn't implement this?</p>