nvarchar notation accepted?
in [PgSql]
|
Prev: pgsql: Add PGFILEDESCdescription to Makefiles for all /contrib
Next: [HACKERS] Generalized Inverted Generalized Search Tree
From: Peter Eisentraut on 14 May 2010 00:16 On tor, 2010-05-13 at 23:52 -0400, Tom Lane wrote: > Takahiro Itagaki <itagaki.takahiro(a)oss.ntt.co.jp> writes: > > Jaime Casanova <jaime(a)2ndquadrant.com> wrote: > >> i migrate a ms sql server database to postgres and was trying some > >> queries from the application to find if everything works right... > >> when i was looking to those queries i found some that has a notation > >> for nvarchar (ej: campo = N'sometext') > > > Do you have documentation for N'...' literal in SQLServer? > > Does it mean unicode literal? What is the difference from U& literal? > > http://developer.postgresql.org/pgdocs/postgres/sql-syntax-lexical.html > > > PostgreSQL doesn't have nvarchar types (UTF16 in MSSQL), and only > > have mutlti-tyte characters. So I think you can remove N and just > > use "SET client_encoding = UTF8" in the cases. > > Actually, the lexer translates N'foo' to NCHAR 'foo' and then the > grammar treats that just like CHAR 'foo'. In short, the N doesn't do > anything very useful, and it certainly doesn't have any effect on > encoding behavior. I think this is something Tom Lockhart put in ten or > so years back, and never got as far as making it actually do anything > helpful. This should maybe changed to just ignoring the N and treating N'' like ''. -- 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: Florian Pflug on 14 May 2010 06:06 On May 14, 2010, at 5:56 , Jaime Casanova wrote: > On Thu, May 13, 2010 at 10:13 PM, Takahiro Itagaki > <itagaki.takahiro(a)oss.ntt.co.jp> wrote: >> >> Jaime Casanova <jaime(a)2ndquadrant.com> wrote: >> >>> i migrate a ms sql server database to postgres and was trying some >>> queries from the application to find if everything works right... >>> when i was looking to those queries i found some that has a notation >>> for nvarchar (ej: campo = N'sometext') >> >> Do you have documentation for N'...' literal in SQLServer? >> Does it mean unicode literal? What is the difference from U& literal? >> http://developer.postgresql.org/pgdocs/postgres/sql-syntax-lexical.html >> > > nop, only thing i found is about NVARCHAR: > http://msdn.microsoft.com/en-us/library/ms186939.aspx but it has no > examples about the N'' notation although you can find examples of it > use here: http://msdn.microsoft.com/en-us/library/dd776381.aspx#BasicSyntax Without using the N prefixed versions of CHAR, VARCHAR and string literals, MS SQL Server refuses to process characters other than those in the database's character set. It will replace all those characters with '?'. Note that this is not an encoding issue - it will even do so with protocol versions (everything >= 7.0 I think) that use UTF16 on-wire, where those characters can be transmitted just fine. best regards, Florian Pflug -- 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: Jaime Casanova on 6 Jun 2010 22:13 On Thu, May 13, 2010 at 11:00 PM, Tom Lane <tgl(a)sss.pgh.pa.us> wrote: > Jaime Casanova <jaime(a)2ndquadrant.com> writes: >> On Thu, May 13, 2010 at 10:52 PM, Tom Lane <tgl(a)sss.pgh.pa.us> wrote: >>> Actually, the lexer translates N'foo' to NCHAR 'foo' and then the >>> grammar treats that just like CHAR 'foo'. In short, the N doesn't do >>> anything very useful, and it certainly doesn't have any effect on >>> encoding behavior. I think this is something Tom Lockhart put in ten or >>> so years back, and never got as far as making it actually do anything >>> helpful. > >> so, the N'' syntax is fine and i don't need to hunt them as a migration step? > > As long as the implied cast to char(n) doesn't cause you problems, it's > fine. > Is this something we want to document? Maybe something like: """ For historical reasons N'' syntax is also accepted as a string literal. """ or we can even mention the fact that that is useful for sql server migrations? -- Jaime Casanova www.2ndQuadrant.com Soporte y capacitación de PostgreSQL -- 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: Peter Eisentraut on 7 Jun 2010 03:23 On sön, 2010-06-06 at 21:13 -0500, Jaime Casanova wrote: > On Thu, May 13, 2010 at 11:00 PM, Tom Lane <tgl(a)sss.pgh.pa.us> wrote: > > Jaime Casanova <jaime(a)2ndquadrant.com> writes: > >> On Thu, May 13, 2010 at 10:52 PM, Tom Lane <tgl(a)sss.pgh.pa.us> wrote: > >>> Actually, the lexer translates N'foo' to NCHAR 'foo' and then the > >>> grammar treats that just like CHAR 'foo'. In short, the N doesn't do > >>> anything very useful, and it certainly doesn't have any effect on > >>> encoding behavior. I think this is something Tom Lockhart put in ten or > >>> so years back, and never got as far as making it actually do anything > >>> helpful. > > > >> so, the N'' syntax is fine and i don't need to hunt them as a migration step? > > > > As long as the implied cast to char(n) doesn't cause you problems, it's > > fine. > > > > Is this something we want to document? Maybe something like: > """ > For historical reasons N'' syntax is also accepted as a string literal. > """ > > or we can even mention the fact that that is useful for sql server migrations? I don't think it's a historical reason, at least not unless all reasons are to some degree historical. The N'' syntax is in the SQL standard, and so if our implementation matches that, it should be documented as a supported feature, and if it doesn't match it, we should fix it, and perhaps leave it undocumented until we have figured out what we want it to do. (I have not done that analysis.) -- 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: Jaime Casanova on 7 Jun 2010 13:56
On Mon, Jun 7, 2010 at 2:23 AM, Peter Eisentraut <peter_e(a)gmx.net> wrote: > > The N'' syntax is in the SQL standard, > I didn't know that, do you know what paragraph is it? i can't find it -- Jaime Casanova www.2ndQuadrant.com Soporte y capacitación de PostgreSQL -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers |