FreeTDS Development Group

["ZIGLIO, Frediano, VF-IT" <Frediano.Ziglio AT vodafone.com>]

> 
> Simon Talbot wrote:
> > erc = dbbind(dbproc, c+1, bindtype, -1, (BYTE *) data[c].buffer); 
> > 
> > Which is using -1 as the varlen -- I cannot see a 
> definition of what -1
> > as a varlen means anywere, but this would explain why 
> bsqldb exhibited
> > the problem in the version of the library we did most of 
> our work with.
> 
> Gah!  I said the dbbind() rules are arcane, but I thought at least *I*
> knew them!  
> 
> You're right, and our implementation is wrong: dbbind() 
> accepts a varlen
> of 0 to mean "the buffer is big enough, trust me".  The 
> vartype governs
> padding and null-termination.  It's dbconvert() that accepts 
> a destlen of
> -1 and -2, to indicate the kind of termination.  
> 
> Microsoft and Sybase agree on the dbbind() semantics.  They don't for
> dbconvert(); they define -1 differently and only Sybase defines -2. 
> (However, IIRC Microsoft's implementation does trim blanks 
> for a destlen
> of -1.)  We adhere to Sybase semantics -- or, at least, that's what we
> intend.  
> 
> This will be a royal pain to fix.  The padding and termination
> instructions -- as presented through the vartype -- have to 
> be inserted
> into the colinfo structure, and dbnextrow() will have to honor those
> instructions each time a column is fetched to a bound variable.  All
> without disturbing the other libraries.  Such are the joys.  
> 
> Thank you for pointing this out.  There are now two new items 
> on the TODO
> list:
> 
> 1.  Write dbsetnull() and fix the default NULL representations. 
> 2.  Change dbbind() to disallow -1 as a varlen.  
> 
> I suppose you know we also accept patches?  
> 
> Regards, 
> 
> --jkl
> 
> P.S. Freddy, do you have any idea why we have 
> copy_data_to_host_var()?  I
> think we should simply call dbconvert().  
> 

I searched in CVS logs and I found that I applied patch 974778
(http://sourceforge.net/tracker/index.php?func=detail&aid=974778&group_i
d=33106&atid=407808). I searched even ML to see comments but I didn't
find any other informations.

freddy77