title: Why trim in Postgres 9.3 did not do the work?
body: <p>We want to trim the leading and trailing space for <code>resource</code> column in postgres 9.3 and it seems to be a simple job. Here is the SQL:</p>
  <pre><code>update tablename set resource=trim(resource);
  </code></pre>
  <p>The query is executed in postgres admin tool SQL screen successfully. However the space was not trimmed. Then we executed the SQL by specifying the id:</p>
  <pre><code>update tablename set resource=trim(resource) where id=723;
  </code></pre>
  <p>It returned:</p>
  <pre><code>Query returned successfully: one row affected, 12 ms execution time.
  </code></pre>
  <p>However the result is the same and there is no update. The same SQL is executed in terminal window and nothing happens.</p>
  <p>Why <code>trim</code> did not work here?</p>