RE: Null function parameters

Thanks Anatoly

So if I understand you correctly you can't pass more than one NULL int into
a function?

Therefore Newbe DBA type question: -
Is this a shortcoming in postgres or is it to be expected when dealing with
transactions?
If it is a shotcoming are there any plans to include it in future releases?

Regards

Graham

-----Original Message-----
From: tolik(at)tolikus(dot)hq(dot)aaanet(dot)ru [mailto:tolik(at)tolikus(dot)hq(dot)aaanet(dot)ru]On
Behalf Of Anatoly K. Lasareff
Sent: 23 August 2000 12:46
To: Tom Lane
Cc: Graham Vickrage; postgresql
Subject: Re: [SQL] Null function parameters

>>>>> "TL" == Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:

TL> "Graham Vickrage" <graham(at)digitalplanit(dot)com> writes:
>> However my understanding was that if the default value is SQL NULL then
any
>> values passed into the function that are null would be treated as
'NULL'.

TL> Not sure what you think you meant by that, but a null is a null. If
you
TL> declared the table column as NOT NULL then Postgres is doing exactly
TL> what it should. You may wish to code the insert along the lines of

TL> INSERT INTO table VALUES (..., COALESCE($1, suitable-default), ...)

TL> COALESCE is a handy notation for "value1 unless it's NULL, in which
case
TL> value2".

TL> regards, tom lane

But unfortunately we have no answer for primary question:

| Why if we pass to function ONLY ONE null agument all the oters |
| argumenta in function's boby are null too? |
| Or: is it possible to pass null arguments into plpgsql functions? |

Example.

create function a(int, int) returns int as '
begin
raise notice ''1: % 2: %'', $1, $2;

if $1 is null then
return $2;
end if;

return $1;
end;
' language 'plpgsql';

tolik=# select a(1,2);
NOTICE: 1: 1 2: 2
a
---
1
(1 row)

tolik=# select a(null,2);
NOTICE: 1: <NULL> 2: <NULL>
a
---

(1 row)

--
Anatoly K. Lasareff Email: tolik(at)aaanet(dot)ru