I'm working with Oracle Form Builder and I needed a trigger to check
something when I delete a record. I made a trigger on ' KEY-DELREC ' and
I've written this code ( it's just a test, the delete statement isn't
ready ):

----
DECLARE
aantal number(8);
BEGIN
select count(*)
into aantal
from voorstellingen v
where :zalen.zaalnr = v.zaalnr;
show_error_alert('This query has ' + aantal + ' records');
raise form_trigger_failure;
END;
----

LITTLE EXPLANATION:
Another table called 'voorstellingen' can have zero or more records with
zaalnr as foreign key ( voorstnr as primary key, but this doesn't
matter, I think ). When this table has one or more records, it may not
be deleted. ':zalen.zaalnr' is the primary key of the table 'zalen' wich
I'm working with.

THE PROBLEM:
When I perform this, the code above should give me a message about how
many records the table voorstellingen has. But when I perform it I
receive an unhandled exception: " ORA-06502: PL/SQL: numeric or value
error string ".

Can someone help me please ???

Tommy DN wrote:
[color=blue]
> I'm working with Oracle Form Builder and I needed a trigger to check
> something when I delete a record. I made a trigger on ' KEY-DELREC ' and
> I've written this code ( it's just a test, the delete statement isn't
> ready ):
>
> ----
> DECLARE
> aantal number(8);
> BEGIN
> select count(*)
> into aantal
> from voorstellingen v
> where :zalen.zaalnr = v.zaalnr;
> show_error_alert('This query has ' + aantal + ' records');
> raise form_trigger_failure;
> END;
> ----
>
> LITTLE EXPLANATION:
> Another table called 'voorstellingen' can have zero or more records with
> zaalnr as foreign key ( voorstnr as primary key, but this doesn't
> matter, I think ). When this table has one or more records, it may not
> be deleted. ':zalen.zaalnr' is the primary key of the table 'zalen' wich
> I'm working with.
>
> THE PROBLEM:
> When I perform this, the code above should give me a message about how
> many records the table voorstellingen has. But when I perform it I
> receive an unhandled exception: " ORA-06502: PL/SQL: numeric or value
> error string ".
>
> Can someone help me please ???[/color]

Please do not post your question to every usenet group you can spell.
The appropriate group for Forms is c.d.o.tools.

There are two problems with your statement. The first, as pointed out
by Dirk is you concatenate strings with || not +.

The second is that aantal is a number so you should do an explicit
casting. Your statement should be:

show_error_alert('This query has ' || TO_CHAR(aantal) || ' records');
--
Daniel A. Morgan
University of Washington
damorgan@x.washington.edu
(replace 'x' with 'u' to respond)

DA Morgan wrote:[color=blue]
> Tommy DN wrote:
>[color=green]
>> I'm working with Oracle Form Builder and I needed a trigger to check
>> something when I delete a record. I made a trigger on ' KEY-DELREC '
>> and I've written this code ( it's just a test, the delete statement
>> isn't ready ):
>>
>> ----
>> DECLARE
>> aantal number(8);
>> BEGIN
>> select count(*)
>> into aantal
>> from voorstellingen v
>> where :zalen.zaalnr = v.zaalnr;
>> show_error_alert('This query has ' + aantal + ' records');
>> raise form_trigger_failure;
>> END;
>> ----
>>
>> LITTLE EXPLANATION:
>> Another table called 'voorstellingen' can have zero or more records
>> with zaalnr as foreign key ( voorstnr as primary key, but this doesn't
>> matter, I think ). When this table has one or more records, it may not
>> be deleted. ':zalen.zaalnr' is the primary key of the table 'zalen'
>> wich I'm working with.
>>
>> THE PROBLEM:
>> When I perform this, the code above should give me a message about how
>> many records the table voorstellingen has. But when I perform it I
>> receive an unhandled exception: " ORA-06502: PL/SQL: numeric or value
>> error string ".
>>
>> Can someone help me please ???[/color]
>
>
> Please do not post your question to every usenet group you can spell.
> The appropriate group for Forms is c.d.o.tools.
>
> There are two problems with your statement. The first, as pointed out
> by Dirk is you concatenate strings with || not +.
>
> The second is that aantal is a number so you should do an explicit
> casting. Your statement should be:
>
> show_error_alert('This query has ' || TO_CHAR(aantal) || ' records');[/color]

OK thanks, it works. So, I consider this topic closed.