AW: Why RPG IV Sucks -- RPG400-L

Hi Barbara,

What I never understood is:

Why a date that is stored as 4Byte integer must be converted into a readable
representation.
It must be faster to directly compare and calculate with this integer
values, instead of
converting to a readable representation and than to recorvert it.
This pecularity can cause a lot of problems when using embedded SQL.
SQL (or better the variables used in the API calls) get defined with the
date format at compile time,
what is specified in the compile command or in an SET OPTION Statement.
All other date fields use the date format defined in the D-Specs, H-Specs or
*ISO,
depending on their definition.

SQL on the other hand does not care about the date format.
Sure, it is used to make a date readable, but you don't get an error,
if the date is out of range.
It is even possible to insert records and calulation with dates,
if they are out of range.

Birgitta

-----Ursprungliche Nachricht-----
Von: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx]Im Auftrag von Bob Cozzi
Gesendet: Samstag, 29. Januar 2005 14:48
An: 'RPG programming on the AS400 / iSeries'
Betreff: RE: Why RPG IV Sucks


>>Packed VS. Zoned...
Barbara,

But numeric fields won't crash the program if their format is different.
A 7-digit packed field can contain the same value range as a 7-digit zoned
numeric field.

Really, perhaps this should have been "Why Date Fields Suck" because if all
date fields could hold the same date range, then the point would be moot.
But I think we had date fields first so... :)

-Bob


-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-bounces@xxxxxxxxxxxx]
On Behalf Of Barbara Morris
Sent: Friday, January 28, 2005 8:04 PM
To: rpg400-l@xxxxxxxxxxxx
Subject: Re: Why RPG IV Sucks

Holden Tommy wrote:
>
> sounds reasonable that if the date field is defined with a date format
that
> the RPG compiler SHOULD keep the date format...
>
> maybe a DCR might help???  FWIW, I can generally deal with those type
> scenarios & quirks ok but on a bad day....they frustrate me immensely!!!
>

This is the same external format vs internal format thing that you get
with fields that are zoned in the database and packed in the program.
It's behaving that way because RPG allows you to have the fields in
different files with different formats, so it uses a standard default
format for the internal fields.

The best way around it is to define an externally-described data
structure with the fields in the file.  The ext-desc DS will get the
fields exactly the way they are in the file.

For the date thing, you could put DATFMT(*YMD) in the H spec, and then
the dates would default to *YMD instead of *ISO.

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