Re: Null function parameters
От | tolik@aaanet.ru (Anatoly K. Lasareff) |
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Тема | Re: Null function parameters |
Дата | |
Msg-id | 86em3gumhr.fsf@tolikus.hq.aaanet.ru обсуждение исходный текст |
Ответ на | RE: Null function parameters ("Graham Vickrage" <graham@digitalplanit.com>) |
Ответы |
Re: Null function parameters
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Список | pgsql-sql |
>>>>> "GV" == Graham Vickrage <graham@digitalplanit.com> writes: GV> Thanks AnatolyGV> So if I understand you correctly you can't pass more than one NULL int intoGV> a function? I'afraid no. My question is: if I pass one null argument into function then all other argumens, which are not null, became null inside function body. GV> Therefore Newbe DBA type question: -GV> Is this a shortcoming in postgres or is it to be expected when dealing withGV>transactions?GV> If it is a shotcoming are there any plans to include it in future releases? GV> Regards GV> Graham GV> -----Original Message-----GV> From: tolik@tolikus.hq.aaanet.ru [mailto:tolik@tolikus.hq.aaanet.ru]OnGV> Behalf Of AnatolyK. LasareffGV> Sent: 23 August 2000 12:46GV> To: Tom LaneGV> Cc: Graham Vickrage; postgresqlGV> Subject: Re: [SQL]Null function parameters >>>>> "TL" == Tom Lane <tgl@sss.pgh.pa.us> writes: TL> "Graham Vickrage" <graham@digitalplanit.com> writes:>>> However my understanding was that if the default value is SQLNULL thenGV> any>>> values passed into the function that are null would be treated asGV> 'NULL'. TL> Not sure what you think you meant by that, but a null is a null. IfGV> youTL> declared the table column as NOT NULLthen Postgres is doing exactlyTL> 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 whichGV> caseTL> value2". TL> regards, tom lane GV> But unfortunately we have no answer for primary question: GV> | Why if we pass to function ONLY ONE null agument all the oters |GV> | argumenta in function's boby are null too? |GV> | Or: is it possible to pass null arguments into plpgsql functions? | GV> Example. GV> create function a(int, int) returns int as 'GV> beginGV> raise notice ''1: % 2: %'', $1, $2; GV> if $1 is null thenGV> return $2;GV> end if; GV> return $1;GV> end;GV> ' language 'plpgsql'; GV> tolik=# select a(1,2);GV> NOTICE: 1: 1 2: 2GV> aGV> ---GV> 1GV> (1 row) GV> tolik=# select a(null,2);GV> NOTICE: 1: <NULL> 2: <NULL>GV> aGV> --- GV> (1 row) -- Anatoly K. Lasareff Email: tolik@aaanet.ru
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