Re: Column-level triggers in docs

Thom Brown <thom@linux.com> writes:
> I notice that the 9.0 docs page for CREATE TRIGGER doesn't indicate
> column-level syntax in the synopsis:
> http://www.postgresql.org/docs/9.0/static/sql-createtrigger.html

My recollection is that we did it that way deliberately.  The originally
submitted patch tried to explain this as part of the syntax diagram,
but it was (a) confusing and (b) not correct in detail.

> So it would read something like:

> CREATE TRIGGER name { BEFORE | AFTER } { event [ OF column_name [, ...
> ] ] [ OR ... ] }

If you do this then it looks like "OF column_name" can be attached to
all four event types, which is wrong.  So you end up needing just as
much verbal annotation as in the current arrangement.

            regards, tom lane