title: SQL query with condition when one field not equal to another
body: <p>Let's say we have fields:  id | content | updateTime | creationTime</p>
  
  <p>When insertion done both updateTime and creationTime get filled with current time. On update only updateTime field get changed. When I need to find all data created on '2012-06-28' I simply use: </p>
  
  <pre><code>SELECT id, content FROM tbl WHERE creationTime LIKE '2012-06-28%'`
  </code></pre>
  
  <p>But to get all data that was updated excluding created data I need to use something like this:</p>
  
  <pre><code>SELECT id, content FROM tbl WHERE creationTime LIKE '2012-06-28%' AND creationTime != updateTime
  </code></pre>
  
  <p>This can't work, obviously. Though I could find all updated data by comparing values of two 'time' collumns inside php, I'd still love to do it inside query. </p>
  
  <p>UPD: Well, it turns out that I was absolutely unaware that sql allows not only compare value of a field with a given variable, number... but also it can compare value of one field with another.  </p>