Re: Flat File Help?

It has always been my understanding that a 'flat file' is 
a database that is NOT a "relational database". 

In other words, the 'flat file' approach puts all the information into 
one large table.  The relational approach divides data into two or 
more tables and then relates the tables.

Us old RPG programmers know about these flat files and the RPG 
cycle!

From:                   boothm@earth.Goddard.edu
To:                     RPG400-L@midrange.com
Copies to:              
Subject:                Re: Flat File Help?
Date sent:              Thu, 03 Feb 2000 16:19:08 GMT
Send reply to:          RPG400-L@midrange.com

What is a "flat file"?  That part still eludes me.

In the example you offer though, make the file IP and forget the read 
loops and setting on LR.  But add in an input record type to catch any 
errant records (I used 99 here).  If you are going to program-describe 
anyway, take advantage of the work already done for you by the compiler. 
(I also added the L1 indicator because if he has both header and detail, 
I'd bet he'll need L1 break processing.)

FINPFILE   IP   F  250        DISK
IINPFILE   NS  01    1 CH
I                                  1    1  RCDTPH L1
I                                  2    5  HDFLD1
I                                  6   15  HDFLD2
I          NS  02    1 CD
I                                  1    1  RCDTPD L1
I                                  2    5  DTFLD1
I                                  6   15  DTFLD2
I          NS  99
 *
C  L1               EXSR L1DETSR
C                   IF        *in01 = *ON
 * perform header record procesing
C                   ENDIF
 *
C                   IF        *in02 = *ON
 * perform detail record procesing
C                   ENDIF
 *
CL1                 EXSR L1TOTSR
..etc..

_______________________
Booth Martin
boothm@earth.goddard.edu
http://www.spy.net/~booth
_______________________




watern@cbs.fiserv.com
Sent by: owner-rpg400-l@midrange.com
02/03/2000 03:37 AM
Please respond to RPG400-L

 
        To:     RPG400-L@midrange.com
        cc: 
        Subject:        Re: Flat File Help?





Hi,

In RPG, flat files are processed as "program described files".
On the F-spec you specify the record length for the file.
On the I-specs you specify the structure of the records in the file.
If there is more than one record type in the file (eg
header,detail,trailers), the I-specs can cope with this too.

I would check out the RPG400 User Guide and ILE RPG400 programmers guide
for general discussion on program described files vs the traditional
externally described files.
The RPG400 Reference and ILE RPG400 Reference will give you exact details
required for coding with program described files.

If there is only one record type in the file you could consider building 
an
externally described file and copying the data to it using cpyf
fmtopt(*nochk). This would allow you to process in the "normal" way.

Otherwise, a typical program processing a program described file would 
look
something like:-

FINPFILE   IF   F  250        DISK
IINPFILE   AA  01    1 CH
I                                  1    1  RCDTPH
I                                  2    5  HDFLD1
I                                  6   15  HDFLD2
IINPFILE   AB  02    1 CD
I                                  1    1  RCDTPD
I                                  2    5  DTFLD1
I                                  6   15  DTFLD2
 *
C                   EVAL      *IN01 = *OFF
C                   EVAL      *IN02 = *OFF
C                   READ      INPFILE
 *
C                   IF        *in01 = *ON
 * perform header record procesing
C                   ENDIF
 *
C                   IF        *in02 = *ON
 * perform detail record procesing
C                   ENDIF
 *
..etc..

Of course your mainline would code a loop to read through the file until 
no
more records, but this is the jist of what you need.

I will leave you to find out what the f-spec & i-spec coding actually does
from the reference manuals.


hth


<snip>  ...  Could anyone tell me where I might find some
information or an example of a program that reads a
flat file? Any help would greatly be appreciated.   <endsnip>



+---
| 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
+---




+---
| 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
+---
+---
| 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
+---