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Old January 22nd, 2010, 12:35 AM posted to microsoft.public.access.tablesdbdesign
Jeff Boyce
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Posts: 8,621
Default Avoiding Redundant Records

It sounds like you are describing the "business rules" of your operation.
It wouldn't matter if you were using Access or Excel or paper and pencil,
those rules would apply (e.g., no customer carries more than one GL policy).

I'm not aware of any built-in business rule enforcer in MS Access. I
believe you'll need to add the validation checks to enforce those rules.

In some of your situations, using a unique index on multiple fields could be
a way to use Access features to enforce your business rules ... but that's
just plain lucky! You'll probably need to figure out some edits/validation
tests for your form, to prevent the users from doing something your business
doesn't permit.

Good luck!

Regards

Jeff Boyce
Microsoft Access MVP

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"oldblindpew" wrote in message
...
CertsPoliciesID is autonumber and therefore the unique primary key for the
junction table. A unique index on the combination of CertID and PolicyID
would prevent redundant Cert/Policy pairs.

But I am also concerned with redundant Agreement/Policy pairs. It is
acceptable for an Agreement to have more than one Cert, but not that the
same
Policy should appear on more than one of their Certs. Enforcing
Cert/Policy
uniqueness alone doesn't prevent this, and the uniqueness of the
CertsPoliciesID key adds nothing.

Similarly, I am concerned to prevent improper combinations resulting from
policy types. No Insured party is going to carry two General Liability
Policies. If we try to attribute two different GL policies to the same
Insured, either by assigning the two policies to the same Cert, or by
assigning them to two different Certs that are in turn tied to the same
Agreement, something is wrong.

Thanks,
oldblindpew

"Piet Linden" wrote:

You could create a unique index on the combination of (CertID,
PolicyID) in the CertsPolicies table. Nothing wrong with that. Then
if your CertsPoliciesID is an autonumber and set to be unique, you
should have everything, right?
.