Re: Matching Records

Well, I can't find the original RPG processing cycle
chart that was in the System/3 RPG manual anywhere on
the net. But HP has their manual online at this
address
http://docs.hp.com/cgi-bin/doc3k/B3031890001.10422/7

It explains how the data buffers are looked at for
matching records and look ahead fields prior to the
record data being transferred to the record fields. I
remember consulting the IBM version of this frequently
when a I was a newbie in 1976.

--- Jerry Adams <jerry@xxxxxxxxxxxxxxx> wrote:

Luv ya, Booth, but you're wrong this time. Only one
indicator from a
Primary/Secondary file set can be on at a time.
Somehow the compiler
"knows" that there's a matching set in the two
files. I started to say
"pair" instead of set, but either file (though
usually the secondary the
way I code) may have multiple records that satisfy
the match. For
example an order header being matched against an
order line file solely
on order number. The line file will (hopefully)
have 1-n matches
against the header.


Say, anyone game for Look Ahead processing?


* Jerry C. Adams
*IBM System i Programmer/Analyst
B&W Wholesale Distributors, Inc.* *
voice
615.995.7024
fax
615.995.1201
email
jerry@xxxxxxxxxxxxxxx
<mailto:jerry@xxxxxxxxxxxxxxx>



Booth Martin wrote:

hmmm... I don't read the manual well enough

sometimes, but I believe

that the MR indicator, and the file processing,

is such that the next

02 is always there, and known. Otherwise there

would be no way for the

program to know which record to grab next. In

other words, when MR is

on, then 01 and 02 are also on. If there is one 01

record and 5 matching

02 records, then MR will stay on while all six

records are processed. If

MR is off then we know we have a widow or an

orphan.

Then again I could be wrong as heck. :)



Joe Pluta wrote:

From: Booth Martin

Why not select?

select
when *INMR and FILE1DS = FILE2DS
* (do nothing)
when *INMR
write MR_Diffs
when *IN01
write NMR_01
when *IN02
write NMR_02
endsl

Isn't that about all of the choices that there

are?

Close, except the comparison of non-key fields is

only valid when both

records are read in, which only happens when

*IN02 is on.

select
when *IN01 and not *INMR
write NMR_01
when not *INMR // *IN02

is implied

write NMR_02
when *IN02 and FILE1DS <> FILE2DS // *INMR

is implied

write MR_Diffs
endsl

You ignore primary matching records entirely

because you can't see the

secondary fields yet. You only process secondary

records if the data fields

don't match.

Joe

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