title: Remove special character from end of string
body: <p>I am looking to remove special characters from the end of a string. </p>
  
  <p>Input:</p>
  
  <pre><code>looking for Oracle help ~(
  looking ~! for Oracle help ~( Stack
  looking ~! for Oracle help ~( Stack ##
  </code></pre>
  
  <p>Output:</p>
  
  <pre><code>looking for Oracle help
  looking ~! for Oracle help ~( Stack
  looking ~! for Oracle help ~( Stack
  </code></pre>
  
  <p>So I just need to remove non-alphanumeric characters from the end of the string only.</p>
  
  <p>I am looking for Oracle SQL query to achieve this.</p>