title: MySQL on update current_timestamp not working
body: <p>I have a mysql table with a column <code>updated_at default current_timestamp on update current_timestamp</code>. </p>
  
  <p>The value for <code>updated_at</code> gets updated whenever I update the row with a query (directly or through php code) but whenever the row is updated by a trigger from some other table the <code>updated_at</code> value does not change. I want that this also to happen.  </p>
  
  <p>Any suggestions? reasons for this problem?</p>
  
  <p>The relevant row of table1</p>
  
  <pre><code>Field             | Type             | Null | Key | Default           | Extra                       
  updated_at        | timestamp        | NO   |     | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP
  </code></pre>
  
  <p>The trigger in table2 updates some coloumns in table1 whenever a certain coloumn2 in table2 is updated. NOTE: the timestamp is not updated in the trigger. I expect MySQL to do that automatically. </p>
  
  <p>Also I am using a Master-Slave replication and the problem is on both the master and the slave. The logging format for master slave replication is statement logging.</p>