Re: Enforce business rule with before insert trigger?

[riccardo bongiovanni]

Andrew,

if u use this solution :

if(condition_1) then
set @insert_failed := concat(@insert_failed, "error message xxx");
elseif(condition_2) then
set @insert_failed := concat(@insert_failed, "error message xxx");
......
elseif(condition_n) then
set @insert_failed := concat(@insert_failed, "error message xxx");


in your trigger, every time the validation fails u can ADD the REAL error message to environment variable.
at the end of the trigger execution your environment variable contains ALL the real error messages.

This solution I think u can apply to every simple or complex trigger.

In this way in your 'real' application scenario users after their sql fails have to read the environment variable where there will be the real error message (not the primary constraints reason).

I hope I was clear. :-)
Riccardo Bongiovanni.