Re: Sorting and filtering subfiles

Jonathan Mason wrote:

>I like the idea, but doesn't this mean
>that you're reading the data twice
>before writing the record to the subfile?
>
>For example:
>
>a) Read record from database file
>b) Write record to QTEMP file
>c) Repeat until end of file...
>
>d) Read record from QTEMP file
>e) Write record to subfile
>f) Repeat until page full or end of file...

Actually.....:

 a) Read record from database file
 b) Write record to subfile
 c) Repeat until end of file...
c1) display subfile
c2) read user's selected column to sort on

 d) Write subfile to "KEYED" QTEMP file with
      fields filled and sort column in "KEY" field
d1) Read QTEMP file
 e) Write record to subfile
 f) Repeat until page full or end of file...


>Presumably the extra key field is a character
>field long enough to hold the largest field on
>the subfile.

Exactly....

Tony Carolla worte:

> What if some of the subfile columns are
> numeric, some are alpha, and some are
> dates?  Could you create one key field
> that could be loaded with all of these
> data types?

The extra key field is a character field long enough to hold the largest
field in the subfile.  The other fields match the subfile which are used to
reload it in the "KEYED" or sorted order.   When filling the "Keyed" field,
I convert the numeric or dates to alpha...  either using a MOVE {RPG III} or
EVAL "KEYED" = %editc(sort_column:'X') {RPG IV}.

Eurrat Saylor, Jr.


----- Original Message -----
From: "Tony Carolla" <carolla@xxxxxxxxx>
To: "RPG programming on the AS400 / iSeries" <rpg400-l@xxxxxxxxxxxx>
Sent: Tuesday, March 29, 2005 6:54 PM
Subject: Re: Sorting and filtering subfiles


> That sounds like an interesting way of doing it (easier than seven temp
files)
>
> <snip>
> > I write out the subfile to a work file in qtemp,
> > which has the same fields with one extra "KEY" field.  I load the sorted
> > columns data into both the matching field and the "KEY" field, then
reload
> > the subfile from the indexed work file in QTEMP.
> <snip>
>
> What if some of the subfile columns are numeric, some are alpha, and
> some are dates?  Could you create one key field that could be loaded
> with all of these data types?
>
>
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