title: Mysql BEFORE UPDATE trigger activation time
body: <p>I have two InnoDB tables:</p>
  
  <pre><code>CREATE TABLE master(
     id INTEGER UNSIGNED NOT NULL auto_increment PRIMARY KEY
  );
  
  CREATE TABLE details(
     id INTEGER UNSIGNED NOT NULL auto_increment PRIMARY KEY, 
     master_id INTEGER UNSIGNED NOT NULL, CONSTRAINT `byMasterId` 
     FOREIGN KEY (`master_id`) REFERENCES `master`(`id`) ON UPDATE CASCADE ON DELETE CASCADE 
  );
  </code></pre>
  
  <p>And I need a BEFORE UPDATE trigger on master table to do some validation (and cancel an update in some cases). Do cascade changes in details table occur after BEFORE UPDATE trigger?</p>