Re: View updating and nextval() workaround - will this - Mailing list pgsql-hackers

From Richard Huxton
Subject Re: View updating and nextval() workaround - will this
Date
Msg-id 4547733D.2060405@archonet.com
Whole thread Raw
In response to Re: View updating and nextval() workaround - will this ever break?  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Tom Lane wrote:
> Richard Huxton <dev@archonet.com> writes:
>> Basically, I'm wondering if anyone can see a problem with my standard 
>> workaround to the macro-expansion-vs-nextval problem with view.
> 
>> CREATE FUNCTION foobar_ins_fn(p_f1 int4, p_b1 int4) RETURNS void AS $$
>> BEGIN
>>    INSERT INTO foo (f_id, f1) VALUES (nextval('foo_f_id_seq'), p_f1);
>>    INSERT INTO bar (f_id, b1) VALUES (currval('foo_f_id_seq'), p_b1);    
>> END;
>> $$ LANGUAGE plpgsql;
> 
>> CREATE RULE foobar_good_ins AS ON INSERT TO foobar_good
>> DO INSTEAD SELECT foobar_ins_fn(NEW.f1, NEW.b1);
> 
> The main problem with this is that instead of an "INSERT n" command
> completion response, you'll get back a useless SELECT result and then
> "INSERT 0" (because the original INSERT was suppressed by the INSTEAD
> rule).  If your application can deal with that, it's OK, but some don't
> like it ...

I can live with that, so long as there's no 
extremely-clever-look-inside-plpgsql feature anyone is planning.

--   Richard Huxton  Archonet Ltd


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