Re: FreeTDS dbwillconvert discrepancy

Wow that very much did not retain its formatting.. I apologize for the 
broken text.


Joe L


Joe Losco wrote:
> 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.
>