Re: plpgsql raise - parameters can be expressions - Mailing list pgsql-patches

From Pavel Stehule
Subject Re: plpgsql raise - parameters can be expressions
Date
Msg-id Pine.LNX.4.44.0506131806530.18739-100000@kix.fsv.cvut.cz
Whole thread Raw
In response to Re: plpgsql raise - parameters can be expressions  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: plpgsql raise - parameters can be expressions
List pgsql-patches
> That doesn't bother me either, seeing that an undefined variable isn't
> detected at compile time anywhere else.  However, fixing the SQLSTATE
> tests by removing them doesn't seem like a great solution ...
>
> > BTW, another easy improvement in this area is changing the RAISE format
> > string to allow it to be an expression, rather than only a string literal.
>
> I would sort of have expected this to get done at the same time.
>
> Actually, the reason I didn't do something about RAISE in 8.0 was that
> I thought we should reconsider the whole design of the statement: it
> desperately needs to be fixed so that you can specify the SQLSTATE to
> be thrown, and so that you can re-throw the same exception you caught.
> (Note that SQLERRM is not really a solution to that: you might think
> something like "RAISE EXCEPTION SQLSTATE, '%', SQLERRM" would do,
> but it loses information, namely all the auxiliary fields.)
>
> Ideas?

only RAISE? Without parameters can be used only in block. It's same scope
like SQLERRM and SQLSTATE.

Oracle can define variables with type EXCEPTION. This all what we need -
identificator. For value of exception Oracle use PRAGMA EXCEPTION_INIT -
for SQLCODE value. PostgreSQL don't suport SQLCODE, then PRAGMA is
irelevant, but what:

DECLARE my_exception EXCEPTION = '22012'; -- division by zero
BEGIN
  RAISE my_exception; -- named exception; -- no params
  EXCEPTION WHEN division_by_zero THEN
    my_exception ~ division by zero
  END;

----------or----------------
  EXCEPTIO WHEN my_exception THEN
    ...
  END

all variants are legal. I can use user's exception
with default unique value from predefined interval too.

DECLARE my_exception EXCEPTION;

regards
Pavel Stehule

p.s.

>
>             regards, tom lane
>


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