title: PostgreSQL Regular Expression - Excluding strings with numbers
body: <p>I am starting with Postgre Regular Expressions, working on PostgreSQL 8.3 version.</p>
  
  <p>I have a table of records as following:</p>
  
  <pre><code>record
  -----------
  a  
  ab
  abc  
  123abc 
  132abc
  123ABC  
  abc123
  4567  
  5678
  6789  
  </code></pre>
  
  <p>I was going through a simple tutorial:
  <a href="http://www.oreillynet.com/pub/a/databases/2006/02/02/postgresq_regexes.html?page=2" rel="noreferrer"> www.oreillynet.com</a>.
  Everything seemed clear to me until I came to the following query:  </p>
  
  <pre><code>SELECT record FROM myrecords WHERE record ~ '[^0-9]';
  </code></pre>
  
  <p>The tutorail says:</p>
  
  <blockquote>
    <p>this expression returns strings that don't include digits.</p>
  </blockquote>
  
  <p>But it returned following output to me:</p>
  
  <pre><code>output
  ------
  a
  ab
  abc
  123abc
  132abc
  123ABC
  abc123
  </code></pre>
  
  <p>Can anyone explain me this behaviour, please? I am then struggling with another expression on that site trying to exclude strings that include digits AND lower-case letters in the same string.</p>