Обсуждение: Triggers
Hello, I have this doubt since I started using PostgreSQL, a few months ago.
Why triggers are defined that way? I mean, in others DBMS you simply write:
CREATE TRIGGER <trigger_name> ... bla bla bla
BEGIN
....
END;
Why you should write a function first and then the trigger, which must call that function?
What are the advantages/disadvantages of that? Where can I find more information?
--
Germán Hüttemann Arza
Why triggers are defined that way? I mean, in others DBMS you simply write:
CREATE TRIGGER <trigger_name> ... bla bla bla
BEGIN
....
END;
Why you should write a function first and then the trigger, which must call that function?
What are the advantages/disadvantages of that? Where can I find more information?
--
Germán Hüttemann Arza
> Why you should write a function first and then the trigger, which must > call that function? > > What are the advantages/disadvantages of that? Where can I find more > information? The PG way seems very natural to me: you can write functions that do something and then have many triggers call that same function. Also there's not just PL/PGSQL: you might want to define a function in C or Perl and then have a trigger call it. Bye, Chris. -- Chris Mair http://www.1006.org
Chris Mair <chrisnospam@1006.org> writes: >> Why you should write a function first and then the trigger, which must >> call that function? > ... there's not just PL/PGSQL: you might want > to define a function in C or Perl and then have a trigger call it. Right, that's the real reason: this approach doesn't constrain which PL you can write your triggers in. regards, tom lane