Re: strange construct with RETURN within plpgsql

On Fri, Feb 16, 2018 at 6:08 AM, mariusz <marius(at)mtvk(dot)pl> wrote:

> On Fri, 2018-02-16 at 05:40 -0700, David G. Johnston wrote:
> > On Fri, Feb 16, 2018 at 5:31 AM, mariusz <marius(at)mtvk(dot)pl> wrote:
> >
> > so, if there is a reason for such a construct and it does
> > something i
> > didn't notice, please let me know what is the purpose of
> > keyword RETURN
> > after a valid statement.
> >
> >
> > ​
> > https://www.postgresql.org/docs/10/static/plpgsql-
> control-structures.html#PLPGSQL-STATEMENTS-RETURNING
> >
> yes, i know what RETURN does and when it does not exit from function
> (like RETURN NEXT or RETURN QUERY), i know that part of docs, even read
> that again and again before sending, but i must be blind, because i
> cannot see any mention of
> <statement> RETURN;
> where that RETURN keyword does nothing (note the lack of ; before
> return)
> maybe knowing all that i just pass the docs too fast, but i honestly
> cannot see why is this allowed.
>
> the only similar thing which comes to my mind is a statement with
> RETURNING ... clause within cte, but it's not the case here (nor the
> same spelling)
>

​Yeah, I failed to grasp the entire question.

Pavel's answer covers this; RETURN is not a reserved word and thus it is
not an error to use it as a column label - and in this context that is how
RETURN is being parsed.

Typos that just happen be valid syntax is a general problem in a
declarative language like SQL

It would be interesting if (some?) queries supplied to the pl/pgsql
executor could be made to fail if column or table aliases were present -
though at this point it would never be accepted. Maybe something like
plpgsql_check (static analyzer) could point these out?

David J.
​