Re: Passing unicode strings to prepare method and other unicode questions

Tim Bunce wrote:
> On Sun, Aug 31, 2008 at 11:47:38PM +0100, Martin J. Evans wrote:
>> Tim Bunce wrote:
>>> On Fri, Aug 29, 2008 at 12:37:48PM +0100, Martin Evans wrote:
>>>   
>>>> Martin Evans wrote:
>>>>     
>>>>> dbd_st_prepare and dbd_db_login6 both take char* and not the original SV 
>>>>> so how can I tell if the strings are utf8 encoded or not?
>>>>>
>>>>> What I'd like to be able to do (in ODBC terms is):
>>>>>
>>>>> In dbd_db_login6
>>>>>   test if connection string has utf8 set on it
>>>>>   if (utf8on)
>>>>>     convert utf8 to utf16 (that is what ODBC wide functions use)
>>>>>     call SQLDriverConnectW
>>>>>   else
>>>>>     call SQLDriverConnect (this is the ANSI version)
>>>>>
>>>>> Similarly in prepare where a number of people have unicode column or 
>>>>> table names and hence want to do "select unicode_column_name from 
>>>>> table".
>>>>>
>>>>> Is this what dbd_st_prepare_sv (as opposed to dbd_st_prepare) is for? 
>>>>> and should there be a dbd_db_login6_sv?
>>> Yes, and yes.
>>>   
>> Thanks Tim. So how do I get a login6_sv? (I've got an awful feeling you are 
>> going to say send a patch).
> 
> Your feeling is spot on. Should be trivial though. There are several
> similar cases in Driver.xst already.
> 
> Thanks for working on this Martin!
> 
> Tim.

Ok, as you say the change is trivial for a unicode username and password:

#ifdef dbd_db_login6_sv
     ST(0) = dbd_db_login6(dbh, imp_dbh, dbname, username, password, 
attribs) ? &sv_yes : &sv_no;
#elif defined(dbd_db_login6)
     ST(0) = dbd_db_login6(dbh, imp_dbh, dbname, u, p, attribs) ? 
&sv_yes : &sv_no;
#else
     ST(0) = dbd_db_login( dbh, imp_dbh, dbname, u, p) ? &sv_yes : &sv_no;
#endif

and an additional line in dbd_xsh.h I presume but not "dbname" which is 
the one I'd really like as it is currently char *. How do I get dbname 
to be an SV - as you may have guessed by now I'm not an XS expert. Is it 
just a case of changing my DBD::ODBC::db::_login to say it is an SV*?

Thanks for the pointers.

Martin
-- 
Martin J. Evans
Easysoft Limited
http://www.easysoft.com

>>>> Also, to use dbd_st_prepare_sv am I supposed to add something like the 
>>>> following to ODBC.xs:
>>>>
>>>> #include "ODBC.h"
>>>> # the following line added:
>>>> #define dbd_st_prepare_sv dbd_st_prepare_sv
>>> Each driver should have a .h file that contains a bunch of line like
>>>
>>>     #define dbd_db_do               ora_db_do
>>>     #define dbd_db_commit           ora_db_commit
>>>     #define dbd_db_rollback         ora_db_rollback
>>>     ...etc...
>>>
>>> They indicate which methods have implementations in C, which
>>> implementation should be used, i.e. dbd_db_login vs dbd_db_login6,
>>> and they ensure that the C function names are unique so multiple drivers
>>> can be statically linked into the same executable. (Though few people
>>> care about static linking these days.)
>>>
>>> The "Implementation header dbdimp.h" in the DBI::DBD docs talks about this.
>>>
>>> So, to answer your question, alongside your existing set of #defines
>>> you'd add #define dbd_st_prepare_sv odbc_st_prepare_sv.
>>>
>>> (It's probably a personal preference if you name the actual C function
>>> odbc_st_prepare_sv, or name it dbd_st_prepare_sv and let the macro
>>> rename it for you.)
>>>
>>> Tim.
>> Sorted, thank you.
>>
>> I've got a load of unicode changes for DBD::ODBC but I'm still not 100% 
>> about some of them. I keep getting emails from people tapping in stuff like 
>> japanese (JIS) strings into their SQL and expecting it to just work across 
>> different platforms. To add to the confusion ODBC (as far as Microsoft is 
>> concerned) already defines SQLxxxW functions which are (wide - ha, i.e., 
>> UCS-2 versions for the normal ANSI functions). The current changes would 
>> allow connection to a unicode data source name (if I've got login6_sv), 
>> preparing of unicode SQL and support for unicode column and table names - 
>> all decode_utf8'ed to perl.
>>
>> As an aside, if anyone reading this has wanted any kind of unicode support 
>> in DBD::ODBC (which is not already there) please get in contact with me.
>>
>> Martin
> 
>