The number list is a little tricky. The numbers are assigned in the main item
list at the beginning of the schema. If you remove an item from a dataset, the
numbers do not change.  If you remove an item from the main item list, you will
tumble all the numeric lists.  So, if you use number lists, make sure you a)
never delete an item from the database and b) always add a new item at the end
of the item declarations.

In order not to have to worry about the item number changing, I have always
built my numeric lists at the beginning of the programs by using DBINFO calls
converting item names to numbers.  Of course, if you change the names then you
encounter another problem.  The DBINFO calls will fail.

Kind regards,

Denys. . .

Denys Beauchemin
HICOMP
(800) 323-8863  (281) 288-7438         Fax: (281) 355-6879
denys at hicomp.com                             www.hicomp.com


-----Original Message-----
From:   Mark Landin [SMTP:[log in to unmask]]
Sent:   Thursday, 18 November, 1999 8:20 AM
To:     [log in to unmask]
Subject:        Re: Settle an image dispute.

On Wed, 17 Nov 1999 11:17:27 -0500, Timothy Hoefner <[log in to unmask]>
wrote:

>I recall hearing that it is not necessary to recompile a program just =
>because a new item has been added to a dataset.  That is of course that =
>the program declares each item being accessed and that "all-list" is =
>not used on the affected set.   The dispute is that you must recompile =
>regardless of how the list is defined in the program.

"@" and "*" item lists should work just fine without recompiling,
since these are evaluated at run-time, not compile-time. Of course you
will probably have issues with the input buffer for the dataset....

You should't need to recompile programs with named or numbered item
lists either, as long as you don't want to access the new data item in
these programs.

If you are DELETING a data item, I am not sure how that would work,
espeically with numbered item lists. Does IMAGE renumber items in a
dataset if you delete an item from the middle of the dataset?

>Can anyone steer me toward a document that would contain this kind of =
>information.

The IMAGE/SQL manual is authoritative on this.

Question: if you delete a data item from a dataset, does IMAGE
re-number the data items in the dataset, thus invalidating your
numbered item list?