Обсуждение: Trigger function that works with both updates and deletes?
Most of the trigger fuctions I've written work on new and updated records referencing NEW. etc. I will need some of the trigger functions to work with record deletions too. First, when a record is being deleted, OLD refers to the rec just deleted (or about to be deleted)? Second, while I could write two trigger functions, one dealing with add/update, the other with deletes, it's probably neater to have a single trigger function and have it discriminate "am I being called for a delete, or an add/update?" I don't know how to determine the type record change. -- View this message in context: http://www.nabble.com/Trigger-function-that-works-with-both-updates-and-deletes--tf3943732.html#a11186941 Sent from the PostgreSQL - general mailing list archive at Nabble.com.
On Mon, Jun 18, 2007 at 06:07:37PM -0700, novnov wrote: > First, when a record is being deleted, OLD refers to the rec just deleted > (or about to be deleted)? Correct. > Second, while I could write two trigger functions, one dealing with > add/update, the other with deletes, it's probably neater to have a single > trigger function and have it discriminate "am I being called for a delete, > or an add/update?" I don't know how to determine the type record change. In PL/pgSQL you can use TG_OP. See "Trigger Procedures" in the documentation: http://www.postgresql.org/docs/8.2/interactive/plpgsql-trigger.html -- Michael Fuhr
> Second, while I could write two trigger functions, one dealing with
> add/update, the other with deletes, it's probably neater to
> have a single
> trigger function and have it discriminate "am I being called
> for a delete,
> or an add/update?" I don't know how to determine the type
> record change.
I use trigger arguments and determine what to do by:
if TG_ARGV[0] = 'value'
then
....
end if;
Allan
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Perfect, thanks Michael Fuhr wrote: > > On Mon, Jun 18, 2007 at 06:07:37PM -0700, novnov wrote: >> First, when a record is being deleted, OLD refers to the rec just deleted >> (or about to be deleted)? > > Correct. > >> Second, while I could write two trigger functions, one dealing with >> add/update, the other with deletes, it's probably neater to have a single >> trigger function and have it discriminate "am I being called for a >> delete, >> or an add/update?" I don't know how to determine the type record change. > > In PL/pgSQL you can use TG_OP. See "Trigger Procedures" in the > documentation: > > http://www.postgresql.org/docs/8.2/interactive/plpgsql-trigger.html > > -- > Michael Fuhr > > ---------------------------(end of broadcast)--------------------------- > TIP 9: In versions below 8.0, the planner will ignore your desire to > choose an index scan if your joining column's datatypes do not > match > > -- View this message in context: http://www.nabble.com/Trigger-function-that-works-with-both-updates-and-deletes--tf3943732.html#a11189206 Sent from the PostgreSQL - general mailing list archive at Nabble.com.