Re: inserting and updating

[Roland Bouman]

You can't do that - not natively.

The work around is to provoke an error in some way, like setting a NOT NULL column to NULL:

SET NEW.column := NULL;

which may make sense if your trigger is validating input on a NOT NULL column.

Otherwise, you can call a UDF that always fails, see:

http://rpbouman.blogspot.com/2005/11/using-udf-to-raise-errors-from-inside.html

There is also a patch available if you are willing to recompile the server:

http://koke.amedias.org/articles/2007/05/09/hacking-mysql-signal-support-i/

I hope this helps,

Roland Bouman
http://rpbouman.blogspot.com/