title: Delete trailing space from all values
body: <p>I have a table that contains more than 4 thousand rows.  Suppose I have a column named columnname that has values for all rows but each value may have leading and/or trailing blank characters.  So, it might look like this</p>
  
  <pre><code>columname
  "value "
  "value "
  "value "
  ...
  </code></pre>
  
  <p>And I need a query or technique that removes the leading and/or trailing spaces, like this:</p>
  
  <pre><code>columname
  "value"
  "value"
  "value"
  </code></pre>
  
  <p>How can I achieve this? (I use oracle 11g)</p>