Re: Doubt on prerun time array And a doubt about batch job

["Sunil R" <sunil_ramakumar@xxxxxxxxx>]

Buck,

It does a lot. Yours and Richards mail helped a lot.
I have more or less understood the stuff. I have to try it out and get the
thing sealed :)
Thank you very much.
Sunil

----- Original Message -----
From: "Buck Calabro" <Buck.Calabro@commsoft.net>
To: <rpg400-l@midrange.com>
Sent: Thursday, June 27, 2002 7:03 PM
Subject: RE: Doubt on prerun time array And a doubt about batch job


> Hi Sunil!
>
> >And I guess perrcd will come to place
> >when we use compile time arrays right?
>
> Either compile time or prerun time tables/arrays will use PERRCD.  That's
> how we tell the compiler how many elements are on each input record.  For
> instance, you can define an array of month names like this:
>
> FPF2       IT   F   80        DISK
> D MON             S              3    DIM(12) FROMFILE(PF2)
> D                                     PERRCD(1)
>
> and the file PF2 contains 12 records (12 elements, 1 on each record)
> JAN
> FEB
> MAR
> APR
> MAY
> JUN
> JUL
> AUG
> SEP
> OCT
> NOV
> DEC
>
> If you define the array this way:
>
> FPF3       IT   F   80        DISK
> D MON             S              3    DIM(12) FROMFILE(PF3)
> D                                     PERRCD(12)
>
> then the file contains one record (12 elements, 12 on a record)
> JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC
>
> >Has precompile type arrays and Tables runout of steam?
>
> Well, it depends a lot on what you intend to use them for.  The big
problem
> is that it is difficult to change the size of the array without changing
the
> program.  Imagine having a table of US States.  Today (and since 1960)
there
> have been 50 states, so the table would have 50 elements.  Imagine the
> difficulty if Puerto Rico becomes a state.  Now, every RPG program that
has
> the table of states needs to be changed!  If we stored the names in a file
> instead, then no code would have to change, only add the new state into
the
> file and all the programs work properly.
>
> >Also regrading my earlier doubts can you just
> >explain significance what a table is?
> >Is it related to the table that we can
> >create using strsql?
>
> No.  It is not related to an SQL table.
> A table in RPG is a way to quickly store a small amount of data that you
> refer to very often in the program.  Often, this is for converting a code
to
> a meaningful name, like month abbreviations into the month name.
>
> FPF4       IT   F   80        DISK
> D TABABR          S              3    DIM(12) FROMFILE(PF4) PERRCD(1)
> D TABNAM          S             20    DIM(12) ALT(TABABR)
> c     'JUL'         LOOKUP    TABABR        TABNAM                   20
> c                   if        %found
> c...
>
> File PF4 looks like this
> JANJanuary
> FEBFebruary
> MARMarch
> APRApril
> MAYMay
> JUNJune
> JULJuly
> AUGAugust
> SEPSeptember
> OCTOctober
> NOVNovember
> DECDecember
>
> You might use this when a file contains month abbreviations, but you want
to
> print the full name on a report, or show it on the display.
>
> The other place tables are used is to see if data is 'in a list.'  For
> instance, if you were writing a program to print labels for cola bottles,
> some states charge a bottle return deposit fee.  So you put the states
that
> charge a fee in a table, and do a lookup.  If the state you're working
with
> is in the table (don't care what element; it's only important to know that
> it's in there somewhere) then print the fee:
>
> fPF5       IT   F   80        DISK
> d TABDeposit      S              2    DIM(2) FROMFILE(PF5)
> d                                     PERRCD(1)
> c     'NY'          lookup    TABDeposit                             20
> c   20'Deposit!'    dsply
> c  n20'No deposit'  dsply
> c     'CA'          lookup    TABDeposit                             20
> c   20'Deposit!'    dsply
> c  n20'No deposit'  dsply
> c                   seton                                        LR
>
> PF5 contains:
> NJ
> NY
>
> Of course, you would use a field from your database instead of the
literals
> 'NY' and 'CA'.
> Does this help?
>   --buck
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