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

In article <57mqii$eu7_at_newton.pacific.net.sg>,

   N Prabhakar <prabhs_at_po.pacific.net.sg> wrote:

Isnt there a package called DBMS_ALERT to do just this sort of thing?

I've not got any documentation handly, so I can't check it.

>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
>
>

Miles Thomas
Logica UK Ltd
thomasm_at_logica.com
The above are personal opinions, and are not necessarily the opinions of my employer. Received on Tue Dec 03 1996 - 00:00:00 CET