Re: Question: Can I invoke an application process from a trigger?

xhai_at_ix.netcom.com(Xiaohai Zhang) wrote:
>Hi, everybody:
>
>Here is the scenario: I have an executable file myapp.exe and I'd like
>to have it start automatically when a table in Oracle database is
>updated. I am wondering if I can do this by writng a trigger on this
>table. Usually the trigger only consists of the SQL statements which
>can manupulate the data in the database. Is there any command in Oracle
>to invoke an application outside the database?
>
>Thanks for any useful information. My email address is:
>
>Xiaohaiz_at_digitaldj.com
>
>Xiaohai

Hi there,

Try the following.

1. Create a database trigger on the table. send a message through DBMS_PIPE.
2. On the client side, write a timer based event (on forms 4.5) which will poll the DBMS_PIPE.
3. Once the client receives an info from the pipe, you know that the table has been changed.
4. Now execute an host process through forms 4.5 and run your executable on the client side.

Note : If a user enteres a record in your table. The trigger statement will fire and send a message to DBMS_PIPE. However an rollback is issued, I am not sure whether the PIPE message will be rolled back. Please try this on a TRIAL AND ERROR basis.

Wish you good luck. In case the above solution works, please let me know.

Regards

N.Prabhakar Received on Fri Nov 29 1996 - 00:00:00 CET