title: PostgreSQL SELECT only alpha characters on a row
body: <p>I need to <code>SELECT</code> <em>only</em> alpha characters <code>FROM</code> a row though I'm having trouble with the expression. I've tried:</p>
  
  <pre><code>SELECT id, regexp_replace(_column_name_, '0123456789', '') AS _column_alias_
  FROM _table_name_;
  </code></pre>
  
  <p>I know the general gist would only replace numbers however the column only contains alphanumeric characters to begin with.</p>
  
  <p>So if <code>_column_name_</code> contains a value <code>a1b2c3</code> how do I make PostgreSQL return the string <code>abc</code>?</p>