RE: data structure has no valid subfields

[Buck Calabro <Buck.Calabro@xxxxxxxxxxxx>]

Joe wrote:

>One of the things I found when I was writing PSC400 was
>that subfile record formats act a little differently
>than others.  With subfile record formats, even
>output-only fields are returned in the input
>buffer.  Odd?  Yes.  But that's how it works.

<chuckle> I asked IBM this question on my very VERY first subfile program on
S/38.  The answer I got was to read the Fine Manual.  Basically, the idea
behind this aberration is to allow one to read a bunch of DB records, WRITE
them to a subfile and then READ/C them back out without having to go back to
the DB to get the "output only" fields.

For the archives:

I am ashamed to admit that I don't have a single book on subfiles, so I
don't know if any midrange authors point this out, but it is in fact
documented in that Fine old Manual, the Application Display Programming
guide, page 4-13 (Reading an active record) and 4-14 (Reading the next
changed record) have the same wording, to wit:

"The entire record, including response
 indicators (defined at the file level
 and on fields in a subfile record),
 input, output, output/input, and hidden
 fields, is passed to the program, the
 relative record number is placed in the
 data management feedback area, and the
 record is reset to a not changed record."

  --buck