Re: DOU/DOW for READ Loops

Interesting points.  Comments in line.

Joep Beckeringh wrote:

> Uh, we do.
>
> I might stick to that, but you'll probably reply 'Why?' (maybe with more
> than one question mark), so I'll try to answer that obvious question as
> well.
>
> Because:
> 1. We like to see in the source which fields we actually use

That is nice, but I've found that to be real neccessary when I can just
look in the program itself, when it is short.

> 2. We don't like having hundreds of fields from a file in a program, when we
> only need a description.  And no, we don't want an extra logical just for
> the description, and another one for the description and the price, and
> another one ...  And we don't like the risk of having fields overwritten by
> reading another file that happens to have that same field.

We get around this problem by prefixing all variables in DDS with a unique
2 letter identifier.  ARCust is Customer code in ARFile, CMCust is Customer
field in CMFile (Container Movement) etc...  This prevents overlaying as you
describe.  Also, if you don't do this already in your source, all is not lost, 
you
can still use the Prefix keyword on the file spec, Prefix(AR_)

> 3. We always have a library list which contains one or more base
> applications as well as customer modifications.  Most of the times these
> modifications need extra fields in the data base, which would imply (when
> using externally described files in RPG) either having a version of the base
> application(s) compiled against the modified data base, or having separate
> logicals for the base record layout and the extended layout.

Hmm... good point.  Not sure how to get around that one.

> But rest assured, we don't manually type in record layouts: we have our own
> data base tool that generates (amongst others) the record layouts and is
> able to adjust the RPG-specifications.
>
> Joep Beckeringh

Regards,

Jim Langston

When your program blows up in your fast, it must be a Monday!

+---
| This is the RPG/400 Mailing List!
| To submit a new message, send your mail to RPG400-L@midrange.com.
| To subscribe to this list send email to RPG400-L-SUB@midrange.com.
| To unsubscribe from this list send email to RPG400-L-UNSUB@midrange.com.
| Questions should be directed to the list owner/operator: david@midrange.com
+---