Re: [PATCHES] V0.1 patch for TODO Item: SQL-language reference parameters by name.
On 02/11/2007, Gevik Babakhani <[EMAIL PROTECTED]> wrote: > > Hi, > > > what about name's collision? Maybe is better use some prefix, > > like $ or :. Without it we only propagate one problem from > > plpgsql to others languages. > > > Please explain. > > Perhaps I am wrong, but plpgsql handles arsgument names before it > passes the query to be executed. Please see: > > plpgsql/pl_comp.c/do_compile(...)/line: 393 > > Regards, > Gevik. > it's one from mystic bugs: create table t(a integer, b integer); insert into t values(10,20); create function foo(a integer) returns integer as $$ select a from t where a <> b and a = 10; $$ languge sql; select foo(20); output? expected 10, but you will get NULL! Regards Pavel Stehule so some prefixes can help create function foo(a integer) returns integer as $$ select a from t where :a <> b and a = 10; $$ languge sql; Oracle use symbol ':' I don't know what others databases has. Regards Pavel Stehule ---(end of broadcast)--- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
Re: [PATCHES] V0.1 patch for TODO Item: SQL-language reference parameters by name.
"Gevik Babakhani" <[EMAIL PROTECTED]> writes: >> what about name's collision? Maybe is better use some prefix, >> like $ or :. Without it we only propagate one problem from >> plpgsql to others languages. > Please explain. > Perhaps I am wrong, but plpgsql handles arsgument names before it > passes the query to be executed. Which is actually the Wrong Thing to do: really the parameters should be seen as being in a name scope that's outside that of the query (and thus ambiguous names should be resolved first as column names of the query). The proposed patch does this in the right order and so I think that Pavel's concern is without foundation. One point here is that it would be good to be able to qualify the argument names with the function name, for example create function myfunc(x int) ... select ... from t where t.x = myfunc.x If t has a column named x then this will be the only way that the function parameter x can be referenced within that query. We are partway to that point with plpgsql but haven't bitten the bullet of changing the lookup order. Note that this consideration is another reason for having a callback function that's responsible for trying to resolve unresolved names. I certainly wouldn't like to have a notion of "function name" wired into the parser API, and if we did do that it still wouldn't be sufficient for plpgsql which can have multiple block-label namespaces accessible at once. regards, tom lane ---(end of broadcast)--- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
Re: [PATCHES] V0.1 patch for TODO Item: SQL-language reference parameters by name.
"Gevik Babakhani" <[EMAIL PROTECTED]> writes: > I am sending this patch to check if I am on the right track. > So please take a look at this if possible. You seem not to have understood my recommendation to use a callback function. This patch might work nicely for SQL functions but there will be no good way to use it for plpgsql, or probably any other PL function language. If we're going to change the parser API then I'd like to have a more general solution. regards, tom lane ---(end of broadcast)--- TIP 5: don't forget to increase your free space map settings
Re: [PATCHES] V0.1 patch for TODO Item: SQL-language reference parameters by name.
Hi, > what about name's collision? Maybe is better use some prefix, > like $ or :. Without it we only propagate one problem from > plpgsql to others languages. > Please explain. Perhaps I am wrong, but plpgsql handles arsgument names before it passes the query to be executed. Please see: plpgsql/pl_comp.c/do_compile(...)/line: 393 Regards, Gevik. ---(end of broadcast)--- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
Re: [PATCHES] V0.1 patch for TODO Item: SQL-language reference parameters by name.
Noted. Thank you. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Andrew Dunstan Sent: Friday, November 02, 2007 4:19 PM To: Gevik Babakhani Cc: pgsql-patches@postgresql.org Subject: Re: [PATCHES] V0.1 patch for TODO Item: SQL-language reference parameters by name. Gevik Babakhani wrote: > > Hello all, > > > > Hereby an alpha version regarding the: > > TODO Item: SQL-language reference parameters by name. > > > > I am sending this patch to check if I am on the right track. > > So please take a look at this if possible. > Step 1: don't use c++ style comments like this: + //TODO: Check here C89 is basically our standard. gcc -std=c89 will check that it complies. cheers andrew ---(end of broadcast)--- TIP 6: explain analyze is your friend ---(end of broadcast)--- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
Re: [PATCHES] V0.1 patch for TODO Item: SQL-language reference parameters by name.
> Hello all, > > > > Hereby an alpha version regarding the: > > TODO Item: SQL-language reference parameters by name. > > what about name's collision? Maybe is better use some prefix, like $ or :. Without it we only propagate one problem from plpgsql to others languages. It can be more wide used: * named params in prepared statements * named params in SPI * .. Regards Pavel Stehule ---(end of broadcast)--- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
Re: [PATCHES] V0.1 patch for TODO Item: SQL-language reference parameters by name.
Gevik Babakhani wrote: Hello all, Hereby an alpha version regarding the: TODO Item: SQL-language reference parameters by name. I am sending this patch to check if I am on the right track. So please take a look at this if possible. Step 1: don't use c++ style comments like this: + //TODO: Check here C89 is basically our standard. gcc -std=c89 will check that it complies. cheers andrew ---(end of broadcast)--- TIP 6: explain analyze is your friend
