Re: Updatable Columns in Update Trigger

[Andrew Gilfrin]

Hi Vishal

Unfortunately it's not possible to have when conditions on Triggers, in part this is cannot be implemented in MySQL because only allows a single trigger per event/table combination (i.e. only on insert/update/delete trigger per table).

The only way to implement this is to write a generic trigger which then uses if statements to work out if it should fire or not. You mention the overhead of this which I also discuss on my site http://mysql.gilfster.com/page.php?parent_id=2&page_id=2.0.5

At present it will have to be a case of taking the performance hit or not using triggers to implement your requirements.

Andrew Gilfrin
------------------
http://gilfster.blogspot.com
My MySQL related Blog

http://www.mysqldevelopment.com
MySQL Stored Procedure,Trigger, View.... (Just about most things these days) Information