Thread: plpgsql NULL statement (was Re: [GENERAL] Postgres 8.0 -> BEGIN EXCEPTION END Syntax????)
plpgsql NULL statement (was Re: [GENERAL] Postgres 8.0 -> BEGIN EXCEPTION END Syntax????)
From
Tom Lane
Date:
Daniel Schuchardt <daniel_schuchardt@web.de> writes:
> BEGIN
> exception ...
> EXCEPTION
> WHEN OTHERS THEN ?????????????what to write for do nothing?????????
> END;
> in oracle it's
> WHEN OTHERS THEN null;
> but this syntax doesn't work in postgres.
In Postgres you just write nothing at all:
BEGIN...EXCEPTION WHEN OTHERS THENEND;
However, it does appear that Oracle's PL/SQL has such a statement,
and that they don't like empty exception sections (or empty if/then/else
arms, etc), but *require* you to write "NULL;" in these places.
It seems to me that it would ease porting of Oracle functions if
we allowed a NULL statement in plpgsql.
It looks like about five minutes' work to add such a thing ... anyone
have any objections?
regards, tom lane
Re: plpgsql NULL statement (was Re: [GENERAL] Postgres 8.0 -> BEGIN EXCEPTION END Syntax????)
From
"Andrew Dunstan"
Date:
Tom Lane said: > Daniel Schuchardt <daniel_schuchardt@web.de> writes: >> BEGIN >> exception ... >> EXCEPTION >> WHEN OTHERS THEN ?????????????what to write for do nothing????????? >> END; > >> in oracle it's >> WHEN OTHERS THEN null; >> but this syntax doesn't work in postgres. > > In Postgres you just write nothing at all: > > BEGIN > ... > EXCEPTION > WHEN OTHERS THEN > END; > > However, it does appear that Oracle's PL/SQL has such a statement, and > that they don't like empty exception sections (or empty if/then/else > arms, etc), but *require* you to write "NULL;" in these places. > It seems to me that it would ease porting of Oracle functions if > we allowed a NULL statement in plpgsql. > > It looks like about five minutes' work to add such a thing ... anyone > have any objections? > It's got my vote :-) PLSQL is based on Ada and this is an Ada rule. I like the PLSQL/Ada way a lot more than the PostgreSQL example you gave above, which just looks ... odd. cheers andrew
On Mon, 16 Aug 2004, Tom Lane wrote: > > in oracle it's > > WHEN OTHERS THEN null; > > but this syntax doesn't work in postgres. > > It looks like about five minutes' work to add such a thing ... anyone > have any objections? Is NULL above an empty statement in oracle or is it a normal expression (the normal NULL value) so that the above is a shorthand for WHEN OTHERS THEN SELECT NULL; ? -- /Dennis Björklund
Dennis Bjorklund <db@zigo.dhs.org> writes:
> Is NULL above an empty statement in oracle or is it a normal expression
It's an actual empty statement.
> (the normal NULL value) so that the above is a shorthand for
> WHEN OTHERS THEN SELECT NULL;
Even if it were, the point here is to accept standard Oracle coding
without any translation of that sort.
regards, tom lane