Re: SQL state: 42601. Execption handling.

At Tue, 07 Jun 2022 10:36:52 -0400, Tom Lane <tgl@sss.pgh.pa.us> wrote in 
> =?UTF-8?B?0KY=?= <pfunk@mail.ru> writes:
> > -- 2 -- 
> > do  $$ 
> > begin  
> >    select  p.result  from  dbo.func() p  into  v_result; 
> > exception   when  SQLSTATE  '42601'   then
> >      raise   '42601' ;
> >    when   others   then  
> >      raise   'others' ; 
> > end ;
> > $$
> >  
> > --Exception is not handled. This is the question.
> > ERROR:   "v_result"   is   not  a known variable
> > LINE  3 :    select  p.result  from  dbo.func() p  into  v_result;
> 
> This error is thrown by the plpgsql parser, so you can't trap it
> with "exception", any more than you could trap other syntax errors
> detected by the parser.  (As an extreme example, you could certainly
> not trap it if you misspelled "exception".)

FWIW, you can see the difference as the following difference.

=# CREATE OR REPLACE FUNCTION f1() RETURNS void AS  $$ 
declare
v_result  int; 
begin  
   select  p.result  from  dbo.func(d) p  into  v_result; 
end ;
$$ LANGUAGE plpgsql;
CREATE FUNCTION
(Succeeds. That is, plpgsql parser doesn't catch it.)
=# select f1();
ERROR:  column "d" does not exist
(Caught by SQL parser executed at runtime)

=# CREATE OR REPLACE FUNCTION f2() RETURNS void AS  $$ 
begin  
   select  p.result  from  dbo.func() p  into  v_result; 
end ;
$$ LANGUAGE plpgsql;
ERROR:  "v_result" is not a known variable
LINE 3:    select  p.result  from  dbo.func() p  into  v_result; 
(Fails, as plpgsql parser caught it.)

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center