Reiner Dassing <dassing(at)wettzell(dot)ifag(dot)de> writes:
> I have written a very small test procedure to show a possible error
> on PostgreSQL V7.1.1.
The error is yours: you set up the trigger function to return NULL,
which means it's telling the system not to allow the INSERT or UPDATE.
> INSERT INTO test VALUES(1,'2000-10-11 12:00:00',-20.2);
> NOTICE: Fired INSERT
> INSERT 0 0
Note the summary line saying that zero rows were inserted.
> UPDATE test SET value = 1000.0 WHERE epoch = '2000-10-11 12:10:00' AND
> sensor_id = 1;
> UPDATE 0
Here, zero rows were updated, so of course there was nothing to fire
the trigger on.
regards, tom lane