Re: FreeTDS dbwillconvert discrepancy

Il giorno mer, 26/11/2008 alle 12.56 -0500, Joe Losco ha scritto:
> Hello all,
> I'm in the process of writing an application for OS X using FreeTDS and 
> objective c.  I have come to a point however, that I am pretty confused. 
> My application at this point is still using the sample provided with 
> FreeTDS as in http://www.freetds.org/userguide/samplecode.htm but I am 
> beginning to convert it to be part of a GUI application in Cocoa. 
> 
> I first used the sample to make sure that I can use it as shown, and 
> with a specific query.  The sample as shown works completely.  I took 
> the same code and with minor modifications put it into the GUI app and 
> it does not work.  Now to give some more detailed information. 
> 
> My problem that I've narrowed it down to is with this stub of code
> if (SYBCHAR != pcol->type) {           
>                 pcol->size = dbwillconvert(pcol->type, SYBCHAR);
>             }
> 
> I've placed  "printf("name:%s type:%d size:%d\n", pcol->name, 
> pcol->type, pcol->size);" around this piece of code so that I can see 
> the before and after effects.  In the command line pure C application 
> dbwillconvert returns the size of the would be data converted to the 
> correct type.  This then lets the memory be allocated properly in the 
> later calloc that uses pcol->size+1, as well as everything else to work 
> as intended. 
> 
> However, in the Objective C/GUI version it appears to return a Bool.  It 
> seems to return 1 if it is convertable and 0 if it is not.  This 
> obviously messes up the rest of the allocations in the sample resulting 
> in truncation and overflow errors.  I then looked into this farther and 
> found http://www.freetds.org/reference/a00275.html#ga24 which from what 
> I can tell is that the desired effect of that function is to return the 
> bool. 
> 
> I'm not sure where to go to look for any more information.  Any advice 
> is greatly appreciated.
>            

It returns a bool, you could see vendors (Sybase or MS) documentation
(ie
http://manuals.sybase.com/onlinebooks/group-cnarc/cng1110e/dblib/@ebt-link;pt=2814?target=%25N%15_45151_START_RESTART_N%25)

freddy77