Re: Empty string in db-lib
"Jackson, Craig (Gale)" <[email protected]>
| Newsgroups | gmane.comp.db.tds.freetds |
|---|---|
| Message-ID | <[email protected]> |
I believe that the real issue is in the protocol spec and the databases. Sybase, in particular, does not distinguish zero-length strings from NULLs in the database. Is there an expectation that they would be stored differently? Craig -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Damien Churchill Sent: Monday, May 10, 2010 6:21 AM To: [email protected] Cc: FreeTDS Development Group Subject: Re: [freetds] Empty string in db-lib On 10 May 2010 08:22, [email protected] <[email protected]> wrote: > hi, > >>>> Is it possible to send an empty string as a parameter when making rpc >>>> calls? All my efforts so far seem to result in the parameter ending up >>>> being NULL when doing a trace on the server! >>> >>> It works. Cf. src/dblib/unittests/rpc.c. > >>> According to Sybase, "If the value of the RPC parameter is NULL, pass >>> datalen as 0, even if type is a fixed-length datatype." That's what the >>> unit test does, and the server recognizes them as NULL. > >> >From that it looks like it isn't possible to just send an empty string >> '' which of course is different to NULL? Is this a limitation of >> db-lib or the TDS protocol? > > We had the same issue with CTLib. > Search mailing-list archive for "FreeTDS always setting empty > VARCHAR's to NULL" (24 May 2009). > > A similar fix might be required for dblib. > > Ahh excellent, I will have to investigate this a bit further once I have my machine back up and running! Thanks for pointing me in the right direction! Damien _______________________________________________ FreeTDS mailing list [email protected] http://lists.ibiblio.org/mailman/listinfo/freetds