Re: Reading/writing file with NULL fields

It looks like you need to put 1's and 0's in the null map.  Here's a 
description:

http://publib.boulder.ibm.com/cgi-bin/bookmgr/BOOKS/QB3AT702/7.8?SHELF=&DT=19990322162443&CASE=

It's V4R5, but the manuals for the higher releases are *#@!% PDF's :-(

--Dave

On Monday 12 January 2004 06:06, Jevgeni Astanovski wrote:
> Yes. The first level problem is solved.
>
> But still I have a feeling, that something is wrong here.
> Spent a whole day in attempts to write a program, that adds records from
> one null-capable file to another (also null-capable) file. Both files have
> identical structure of 3 fields:
> field1 alphanumeric, no nulls allowed;
> field2 alphanumeric, null capable;
> field3 packed decimal.
> Program works so:
> reads each record from first file, looks if record with identical fields 1
> and 2 exists in second. If not - adds;
> If yes - updates the value of field 3 in second file.
>
> It should be absolutely trivial!
> Cannot make it running...
> I tried simply to add a record to a null-capable file. As soon, as I open
> it with nullcap=y, inserts fail. Eve if inserted record contain no NULL
> fields. If I remove nullcap=y from open, everything works...
>
> Ay advise will appreciated - may be there is some manual, that describes
> these pecularities?
>
> Regards,
> Jevgeni
>
> > -----Original Message-----
> > From: Elvis Budimlic [mailto:ebudimlic@xxxxxxxxxxxxxxxxxxxxxxxxx]
> > Sent: 18. detsember 2003. A. 0:40
> > To: 'C programming iSeries / AS400'
> > Subject: RE: [C400-L] Reading file with NULL fields
> >
> >
> > Jevgeni,
> >
> > You need "rr nullcap=Y" when you open the file so you can
> > handle the null
> > capable fields.
> > If that doesn't suffice you may want to learn more about file
> > handle's null
> > input map (fp->in_null_map).
> >
> > Elvis
> >
> > -----Original Message-----
> > From: c400-l-bounces@xxxxxxxxxxxx
> > [mailto:c400-l-bounces@xxxxxxxxxxxx] On
> > Behalf Of Jevgeni Astanovski
> > Sent: Wednesday, December 17, 2003 4:13 PM
> > To: C programming iSeries / AS400
> > Subject: [C400-L] Reading file with NULL fields
> >
> > There should be some trick about reading files with
> > NULL-capable fields!
> > But I deal with it for the first time....
> >
> > Have a file Y6CPF:
> >
> > A          R Y6CPFR
> > A            CPNC           6A         TEXT('Account number')
> > A            DLP            3A         TEXT('Deal type') ALWNULL
> >
> > Try to read it :
> >
> > fp = _Ropen("*LIBL/Y6CPF", "rr") ;
> >
> > fb = _Rreadf(fp, &Collateral, sizeof(y6cpf), __NO_LOCK) ;
> > while (fb->num_bytes == sizeof(y6cpf))
> > {
> >   ...
> >   fb = _Rreadn(fp, &Collateral, sizeof(y6cpf), __NO_LOCK) ;
> > }
> >
> > Nothing strange, I always do it like this.
> > Program gets out of the loop on first record, having field DLP=NULL.
> > Shit! And my goal was to find just these records...
> > What's wrong? It SHOULD be as simple as usual!
> > Any help will be really appreciated.
> >
> > Jevgeni Astanovski.