Re: iNav

David

DDS has no concept of constraints. You can use the ADDPFCST command to add one to any PF. You can use ALTER TABLE in STRSQL to do the same.

The SQL Reference explains all about constraints, but in brief, you have 4 kinds - primary key, unique key, check, and referential. The first 2 are fairly obvious, I think. Check constraints are like COND in DDS, I think - the value in the column has to satisfy some condition. Referential constraints say that some column or columns in a dependent file has to match a primary or unique key in a parent table. In addition, you can specify that you can't delete a header table record that has matching records in a detail table.

Look at the help for all the parameters on the ADDPFCST to start to get some understanding. That help refers you to the database section of InfoCenter. You can also google for any of the terms "referential constraint" or "check constraint" or "primary key" or "unique key"

Vern

On 12/7/2010 3:08 AM, David FOXWELL wrote:

-----Message d'origine-----
De : midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] De la part de rob@xxxxxxxxx

Of course, this all assumes that you are using Referential
(and other) constraints. After all, how else is it supposed
to know that the item number from the item master goes into
the order detail file?

Of course! Thanks for your help Rob. So if we have no constraints, the database map is not very interesting.
Could you explain a simple constraint so I can try it out? Would this be only applicable for DDL only or has DDS some kind of equivalent?