title: query to extract all rows inserted/updated from different tables
body: <p>I wrote a vb.net code who updates a mysql database.</p>
  
  <p>To check that code works correctly I added a field "Updated" in each table of database containing the timestamp of inserting (o updating).</p>
  
  <p>I can easly extract updated rows from each table but I wonder if it's possible to extract all updated rows with only one query.</p>
  
  <p>Note that tables have different fields and different number of fields (so I wasn't able to use UNION).</p>
  
  <p>Any hint is appreciated.</p>