Just add a PK to the PF. ADDPFCST *PRIKEY then SQL will recognize it as a
unique key...
Thanks,
Tommy Holden
From: "Schutte, Michael D" <Michael_Schutte@xxxxxxxxxxxx>
To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
Date: 11/19/2010 10:37 AM
Subject: RE: time/date as key fields
Sent by: midrange-l-bounces@xxxxxxxxxxxx
I've started with new applications. Makes writing sql select statements a
lot easier since I only need to join on one field.
But in a current project I'm looking to create a unique key on file
created with DDS. The file in DDS was created with a unique key on
Company and Product. However, SQL doesn't recognize it as a unique key
and I cannot use it when creating foreign key constraints link other table
to it. So on this file I created a new unique key with the same key
fields as the DDS file in the test system. It shouldn't take long to
create in production, problem is I think nobody can be accessing the file
at the time of the build.
I'm also curious. I'm wanting to create foreign keys from new SQL tables
for this new project to this master file. Should be okay to do correct?
I'm believing with the foreign key constraint would make gathering data
later faster. There would be no for SQL to look for access path between
the two because it already exists.
-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx [
mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Richard Schoen
Sent: Friday, November 19, 2010 9:42 AM
To: midrange-l@xxxxxxxxxxxx
Subject: Re: time/date as key fields
A combination of _GENUUID, Verns timestamp routine and job info would most
likely guarantee uniqueness :-)
Otherwise an Identity field in the database indeed guarantees it.
Curiousity question:
How many of you are using Identity fields in databases for new
applications ?
In the past we always created the base key such as Customer Number, Order
Number and that was the primary key. Now I think the wisdom is to always
use an identity field for primary key as well as Customer Number, Order
Number, etc.... as indexes.
Would like to hear thoughts ?.....
Regards,
Richard Schoen
RJS Software Systems Inc.
Where Information Meets Innovation
Document Management, Workflow, Report Delivery, Forms and Business
Intelligence
Email: richard@xxxxxxxxxxxxxxx
Web Site:
http://www.rjssoftware.com
Tel: (952) 736-5800
Fax: (952) 736-5801
Toll Free: (888) RJSSOFT
------------------------------
message: 9
date: Fri, 19 Nov 2010 15:07:43 +0100
from: <dieter.bender@xxxxxxxxxxxx>
subject: Re: time/date as key fields
... it depends, maybe for referential constraints, if there are database
relations.
BTW: genUUID on AS/400 is only most likely unique!!! Best choice would be
an
identity column, if uniqueness is needed.
D*B
midrange.com
