Josh Kupershmidt <schmiddy@gmail.com> writes:
> [Moving to -docs]
> On Mon, May 2, 2011 at 12:00 PM, Pavel Stehule <pavel.stehule@gmail.com> wrote:
>> It isn't correct. NEW is not declared in DELETE trigger, OLD isn't
>> declared in INSERT
That claim is flat out wrong.
> If I've understood you correctly, the problem is that the docs claim
> that the variables are defined with a value of NULL, when in fact they
> are undefined. For example, if you try to use variable NEW in a delete
> trigger, you'll get an error message like:
> | ERROR: record "new" is not assigned yet
> | DETAIL: The tuple structure of a not-yet-assigned record is indeterminate.
That is, in fact, exactly the behavior you get if you declare a RECORD
variable and set it to NULL. If these variables were indeed not
declared, you'd get a complaint about "new" not being a known variable.
Observe:
regression=# create function foo(int) returns void as $$
regression$# begin
regression$# new.x := $1;
regression$# end$$ language plpgsql;
ERROR: "new.x" is not a known variable
LINE 3: new.x := $1;
^
versus
regression=# create function foo(int) returns void as $$
regression$# declare new record;
regression$# begin
regression$# new := null;
regression$# new.x := $1;
regression$# end$$ language plpgsql;
CREATE FUNCTION
regression=# select foo(1);
ERROR: record "new" is not assigned yet
DETAIL: The tuple structure of a not-yet-assigned record is indeterminate.
CONTEXT: PL/pgSQL function "foo" line 5 at assignment
regards, tom lane