terryleonardo a écrit :

> Hi Thierry,
>
> If your 2nd trigger expect to qty must be greater than 0, you should
> use constrain instead of trigger. Because you can not delete the
> same row when the table engaged in your updating.
>

i do not understand how i can describe a constraint to replace my trigger
could you explain?

> If your intension is deleting a row in mytable through an update
> query, you had better to make it with delet and update query
> separately.
>

it is difficult to do that, because the use is :
update mytable set qty = qty - avalue;
so in the same query, some rows downs to 0 but other downs to more than
0 (avalue had been calculated to not be greater than the lesser qty)

> In the 3rd trigger, you did not mention which table that the trigger
> lies. I assume it it attached in the same table, and you could
> update new.field[s] within the trigger.
>

you're right it is the same table
i can't just change new.field[s] values because:
1 - the procedure does more than just an update (some selects, and
inserts in other tables) and not only on the current record
2 - the update could be done not throw the trigger so must be in a procedure

> Regards,
>
> Terry
> a DB hobbyist
>
> --- In firebird-support@yahoogroups.com, Tetram Corp <dev@...> wrote:
>
>> is there a way to break a trigger chain?
>>
>> on a table, i've got 3 triggers after update. First is not revelant
>>
>> second does:
>> if (new.qty = 0) then
>> delete from mytable where id = new.id
>>
>> third does:
>> if (new.field = 'T') then
>> execute procedure update_mytable;
>> else
>> execute procedure update_othertable;
>>
>> the problem is that, sometimes, update_mytable assign 0 to the
>>
> field qty.
>
>> so i've got an error saying "too many execution of the same query"
>>
> (not
>
>> sure about the message but sense is there)
>>
>> the solution i used to solve my problem was to change the third
>>
> trigger to
>
>> if ((new.field = 'T') and (new.qty > 0)) then
>> etc
>>
>> except using an exception, is there a way i could use to break the
>> trigger chain ?
>>
>> Thierry
>>
>>