named parameters in SQL functions
in [PgSql]
|
From: "David E. Wheeler" on 15 Nov 2009 13:59 On Nov 15, 2009, at 10:54 AM, Greg Stark wrote: > I'm japh too -- but that doesn't mean grabbing one little aesthetic > from Perl without copying the whole concept behind it makes any sense. > Perl sigils are an important part of the language and are a basic part > of the syntax. They aren't just a "this is a variable" marker. > Dropping one use of them into a language that doesn't use them > anywhere else just makes the language into a mishmash. Well, no, just because we're talking about adopting $var doesn't mean we're trying to turn SQL or PL/pgSQL into Perl. It means that we want to signify that a token is a variable, as opposed to something else (hence sigil). That doesn't make it a mishmash unless you think you suddenly have Perl (or shell) semantics, which would be a pretty weird expectation. > I don't see any purpose to using such markers anyways. We have a > parser, we have a symbol table, we should use them; these identifiers > are just like other identifiers. See the discussion of conflicts with column names in the recent thread. A sigil would eliminate that problem -- and we already have $1 and friends, so this is just an extension of that in my view. Best, David -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: Pavel Stehule on 15 Nov 2009 13:59 2009/11/15 Greg Stark <gsstark(a)mit.edu>: > On Sun, Nov 15, 2009 at 6:42 PM, Pavel Stehule <pavel.stehule(a)gmail.com> wrote: >>> Personally, I like $var, but @var would be okay, and @@var is acceptable. But I'm JAPH, so my biases should be obvious. >> >> @var or @@var should be a break for people from MySQL. @var are r/w in >> MySQL and @@var are global in T-SQL. So people could be confused. > > Besides, do we think MySQL and T-SQL are the heights of good language design? > sure no. But same arguments against to :var should be used to @var. pgscript use it. I don't know the best semantic. But I am not happy from this proposals. I don't see any consistency. Pavel > > -- > greg > -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: Andrew Chernow on 15 Nov 2009 14:13 >> I like the special marker idea. A '$' would be nice because its already in >> use for similar purposes, but I think that would lead to ambiguity with >> dollar quoting. > > no, it should be safe (if you don't use for dollar quoting some like > $variablename$) > Actually, I was thinking of something like $abc$def, where abc and def are variables. Although, this is much less likely than column name conflicts. Other possibles are: $(var), @var@, or %var%. I'd perfer a single character marker but that may not fly. -- Andrew Chernow eSilo, LLC every bit counts http://www.esilo.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: Pavel Stehule on 15 Nov 2009 14:16 2009/11/15 Andrew Chernow <ac(a)esilo.com>: > >>> I like the special marker idea. Â A '$' would be nice because its already >>> in >>> use for similar purposes, but I think that would lead to ambiguity with >>> dollar quoting. >> >> no, it should be safe (if you don't use for dollar quoting some like >> $variablename$) >> > > Actually, I was thinking of something like $abc$def, where abc and def are > variables. Â Although, this is much less likely than column name conflicts. > > Other possibles are: $(var), @var@, or %var%. Â I'd perfer a single character > marker but that may not fly. > single character is my preference too. Pavel > -- > Andrew Chernow > eSilo, LLC > every bit counts > http://www.esilo.com/ > -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: Greg Stark on 15 Nov 2009 14:21
On Sun, Nov 15, 2009 at 6:26 PM, David E. Wheeler <david(a)kineticode.com> wrote: >> Moreover you would still have conflicts possible because sql can quote >> identifiers so people can have columns named "$foo". You would have a >> weird syntactic detail where "$foo" would mean something different >> than $foo even though they're both valid identifiers. > > Same with Foo and "Foo", no? No, that's not the same. The point is that $ is a perfectly valid SQL identifier character and $foo is a perfectly valid identifier. You can always quote any identifier (yes, after case smashing) so you would expect if $foo is a valid identifier then "$foo" would refer to the same identifier. You're introducing a meaning for $foo but saying there's no valid way to quote the identifier to get the same thing. And worse, if you do quote it you get something else entirely different. -- greg -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers |