Обсуждение: Passing arguments to a function called by a trigger
I have an INSERT AFTER trigger that runs on inserts into a specific table. I'm not sure if the function automatically gets all the information that was inserted into the table or whether you have to manually pass it in? If you do have to manually pass it in can someone point me to some examples showing the correct syntax to use? I've read through the PostgreSQL manual on C functions but most of the trigger examples don't take any arguments unfortunately. Also while I am on the subject can anyone recommend a good book on stored procedure programming with PostgreSQL please? I use plpython2u and C for my stored procedures if that makes any difference. Thanks.
Some Developer <someukdeveloper@gmail.com> wrote: > I have an INSERT AFTER trigger that runs on inserts into a specific > table. I'm not sure if the function automatically gets all the > information that was inserted into the table or whether you have to > manually pass it in? NEW.<colum_name> is your friend ;-) Andreas -- Really, I'm not out to destroy Microsoft. That will just be a completely unintentional side effect. (Linus Torvalds) "If I was god, I would recompile penguin with --enable-fly." (unknown) Kaufbach, Saxony, Germany, Europe. N 51.05082°, E 13.56889°
On 27/07/2013 14:05, Andreas Kretschmer wrote: > Some Developer <someukdeveloper@gmail.com> wrote: > >> I have an INSERT AFTER trigger that runs on inserts into a specific >> table. I'm not sure if the function automatically gets all the >> information that was inserted into the table or whether you have to >> manually pass it in? > > NEW.<colum_name> is your friend ;-) > > > Andreas > Thanks for the tip. So I can just use NEW.<whatever> to get the values inserted into the table from inside the function that is called by the trigger? Is there a corresponding OLD as well if I ever want to do a trigger on an UPDATE?
>Is there a corresponding OLD as well if I ever want to do a trigger on an UPDATE? Yes, you are correct. ODL is variable holding the old database row for UPDATE/DELETE operations in row-level triggers and NEW is holding the new database row. To get to know more about trigger just follow the tutorial at http://wiki.postgresql.org/wiki/A_Brief_Real-world_Trigger_Example I am sure u get more idea about it. Regards, Amul Sul -- View this message in context: http://postgresql.1045698.n5.nabble.com/Passing-arguments-to-a-function-called-by-a-trigger-tp5765350p5765394.html Sent from the PostgreSQL - novice mailing list archive at Nabble.com.
On Sat, Jul 27, 2013 at 1:55 PM, Some Developer <someukdeveloper@gmail.com> wrote: > I have an INSERT AFTER trigger that runs on inserts into a specific table. > I'm not sure if the function automatically gets all the information that was > inserted into the table or whether you have to manually pass it in? You have to read the trigger documentation, as already suggested. Moreover here (https://github.com/fluca1978/fluca1978-pg-utils/blob/master/bsdmag/03-server-side-programming/03-trigger-download_path-improved.sql) you can find an example of triggers using also parameters passed at the creation of the trigger (TG_NARGS, TG_ARGV). Luca