Re: Strange bahaviour

Michael Meskes <meskes(at)postgresql(dot)org> writes:
> CREATE FUNCTION footest1(varchar(100)) RETURNS varchar(100) AS '
> DECLARE
> login varchar(100);
> BEGIN
> SELECT INTO login login FROM foo LIMIT 1;
> RETURN login;
> END;
> ' LANGUAGE 'plpgsql';

> The first select returns NULL while the second correctly returns 'abc'.

The NULL is perfectly correct: that's the initial value of the plpgsql
variable. The above is essentially the same as saying
login := login;
It is not "incorrect".

> Now I can guess what happens but I wonder if this is the desired
> behaviour.

Certainly, unless you'd like to disable all use of plpgsql variables in
SQL queries. plpgsql has no way of guessing that "login" in the above
query wasn't intended to reference its variable. Either choose a
different variable name, or qualify the query-variable reference
(eg, foo.login).

regards, tom lane