FreeTDS Development Group

[LacaK <lacak AT zoznam.sk>]

> > Only for explanation:
> > In FreePascal there are different Database Field Types
> > TStringField and TWideStringField, so my attempt was map
> > char, varchar to TStringField
> > nchar, nvarchar to TWideStringField (see 
> > http://docwiki.embarcadero.com/VCL/en/DB.TWideStringField )
> > (text to TMemoField, ntext to TWideMemoField)
> >     
>
> I understand what you want to do. 
Fine ;-) Thanks (I am not native speaker, so sometimes I have problems 
explain what I want)

>  Unfortunately it will be quite
> difficult with db-lib, because FreeTDS intentionally conceals the server
> column definition.  It was a design decision -- maybe not the right one!
> -- but it's very deep in the library.  
>
> As soon as UCS-2 data arrive from the server, they are immediately
> converted to the client's encoding.  The UCS-2 form is discarded.[1]  To
> provide UCS-2 data to FreePascall, you'll have to re-convert!  
>   
Yes, I can re-convert easy (UTF8 -> WideString), but as I wrote I must 
know original server's column type
When speaking about client encodings, there are supported: ISO-8859-1, 
UTF8, UCS2, arn't ?
Is there possibility obtain character data in current system Ansi 
(non-unicode) charset ?
(here I am speaking about Windows environment, I do not know nothing 
about other OS). In Windows there is for example 
WideCharToMultiByte(CP_ACP, ...)

> Getting db-lib to report the server's type and size wouldn't be
> particularly hard.  The TDSCOLUMN structure has a nested on_server
> structure with exactly that information.  That structure could be
> harmlessly added to the DBCOL structure filled by dbcolinfo().  I think if
> you look at dbcolinfo() and dbcoltype(), you'll see what to do.  Look at
> tds_set_column_type() too.  
>   
Thanks. I understand, and I can do it for my own needs, but as I wrote, 
my FreePascal component will link to dblib.dll.
And I do not want provide specialized/modified/customized version of 
dblib.dll (so everybody can use=download and compile FreeTDS dblib.dll 
from www.freetds.org)
So if this functionality will not be included in main stream version of 
dblib, then I can not use it.

If you agree, that we can add this functionality in some way then I can 
try do it and post patch ... then please give me direction, which is the 
preffered method
(for example: extending DBCOL structure by adding:
SHORT ServerType (wType);
DBINT ServerMaxLength (wMaxLength);
-or-
adding new function dbcolwtype()?
-or-
modify existing FreeTDS-only function dbtablecolinfo() which will 
provide original server's column types?
)

TIA
-Laco.