Thanks, I had checked the example before but couldn't make sense out of it in terms of wrapping it in Objective-C. I left it in C now and it works fine.
The trigger I am using now looks like this: CREATE FUNCTION notify_trigger() RETURNS trigger AS $$ DECLARE BEGIN IF ( TG_OP = 'INSERT' ) THEN execute 'NOTIFY ' || TG_TABLE_NAME || '_' || TG_OP || ', ' || NEW.oid; ELSE execute 'NOTIFY ' || TG_TABLE_NAME || '_' || TG_OP || ', ' || OLD.oid; END IF; return NULL; END; $$ LANGUAGE plpgsql; it works if I remove transmission of the OID. If I do transmit the OID I get DETAIL: The tuple structure of a not-yet-assigned record is indeterminate. CONTEXT: PL/pgSQL function "notify_trigger" line 1 at EXECUTE statement The trigger is firing above function AFTER the TG_OP took place. The error is thrown upon insertion. Doesn't the record exist given I trigger AFTER and not BEFORE the operation took palce? Am 30.04.2012 um 09:53 schrieb Albe Laurenz: > Alexander Reichstadt wrote: >> From the documentation I was able to build a trigger firing upon > deletion of a record a function that >> delivers tablename_operation as a notification one needs to subscribe > to. So in terminal I can say >> LISTEN persons_delete and instantly will receive >> >> Asynchronous notification "persons_delete" received from server > process with PID 54790. >> >> if there was a delete. But what I don't fully understand is how to do > this with PQnotifies. Following >> the docu I get no notifications even though I subscribe to them after > successfully connecting to the >> server the same way I do using terminal. >> >> Googling didn't give me examples I was able to use. Please, can > someone help? > > Did you look at the example in the documentation? > http://www.postgresql.org/docs/current/static/libpq-example.html#LIBPQ-E > XAMPLE-2 > > Can you post relevant parts of your code? > > Yours, > Laurenz Albe
