Re: Why a data structure subfield with the same name of a file field does not keep the same data type?

On 2022-12-28 9:56 a.m., Maria Lucia Stoppa wrote:

I have got news!

It looks like free RPG doesn't support DS subfields with the same name of
file's fields either: it derives the subfield length from the database
field but not the data type.
If a DS is created containing the very same STRNUM and STRNAM names as from
the previous example, then the internal file field's variable is stil
packed(5:0) whereas the DS subfield is zoned(5:0).
So, using DS simply to group fields doesn't seem possible in free RPG
anymore.

I really like to find where this is described in the RPG Reference book: I
couldn't find it at all.

This page describes the defaults for the internal format of numeric definitions:
https://www.ibm.com/docs/en/i/7.5?topic=formats-internal-format

If you code a data structure with just the names of the externally-described fields, the numeric subfields will be zoned.

If you want the subfields to have the same data type as the external fields, you need to code a separate externally-described data structure to get the exact types.

In the following example, if the SALARY field in MYFILE is packed, then the SALARY subfield in the MYFILE_TYPES and MYDS data structures will also be packed.

dcl-ds myfile_types extname('MYFILE') qualified template;
end-ds;

dcl-ds myds;
salary like(myfile_types.salary);
...
end-ds;