title: Update field in linked table in firebird
body: <p>I have two tables - card and journal. The card's id (code) is a linker in journal(card-code) 
  .One card can have many journals and I need to update a field(time) in this card table from journal with trigger - I have wrote the current trigger but it has errors.Please help me to locate it.</p>
  
  <pre><code> AS
   DECLARE VARIABLE currentTimeOfChanging timestamp;
  begin
   select current_timestamp from rdb$database into currentTimeOfChanging;
  
   update card
   set card.lastupdate = currentTimeOfChanging;//!error
   where card.code = journal.cardcode
  end
  </code></pre>