Avoiding Redundant Records

It is not clear to me if Agreements, Certs and Policies are standardized in
and of themselves. Presumably they are. It appears that an Agreement can
have one or more Certs and a Cert can have one or more Policies. It appears
that a Cert is (established ??) by someone identified by ProducerID and it
appears that a Policy is provided by someone identified by ProviderID.
Finally it appears that an Agreement is executed with someone identified by
InsuredID. If all the above is true, consider this table structu
TblProducerID
ProducerID
Producer fields ...

TblProvider
ProviderID
Provider fields ...

TblInsured
InsuredID
Insured fields ....

TblAgreement
AgreementID
Agreement fields ...

TblCert
CertID
Cert fields ...

TblPolicy
PolicyID
Policy fields ...

TblCertPolicy
CertPolicyID
CertID
PolicyID

TblAgreementCertPolicy
AgreementCertPolicyID
AgreementID
CertPolicyID

TblAgreementCertPolicyToInsured
AgreementCertPolicyToInsured
AgreementCertPolicyID
InsuredID
IssueDate
etc

This table structure gives you a record of a specific Agreement containing a
specific set of certs where each Cert contains a specific set of policies
issued to a specific Insured identified by InsuredID.

Steve







"oldblindpew" wrote in message
...
It is my understanding that surrogate keys are generally recommended to
ensure uniqueness of records. Is it not true that using surrogate keys
implies taking extra precautions to prevent duplicate records? I mean,
with
surrogate keys there is nothing to prevent the proliferation of multiple
records all containing the same data, but each having a unique key.

I would appreciate your help with this in the following context:

AGREEMENTS
AgrmtID (PK)
InsuredID
Agrmt fields.

CERTS
CertID (PK)
AgrmtID
ProducerID
Cert fields.

POLICIES
PolicyID (PK)
InsuredID
PolicyTypeCode
ProviderID
Policy fields.

CERTSPOLICIES
CertsPoliciesID (PK)
CertID
PolicyID

Note: Any fieldname ending in "ID" is a surrogate key.

An Agreement can have zero or more Certs; a Cert pertains to only one
Agreement, so this is a one-to-many relationship. Each Cert can have one
or
more Policies; the same Policy can be on different Certs, so this is a
many-to-many relationship, hence these two tables are joined by the
CertsPolicies table.

We don't want the same Policy to appear more than once on the same Cert.
I
believe this can be accomplished fairly easily by setting up CertID and
PolicyID as a multi-field unique index in the junction table.

We also have to ensure that the user doesn't inadvertently relate any one
Policy twice to the same Agreement through the use of a second Cert. In
other words, we do not want to see the same Policy on two different Certs
for
the same Agreement. How would this be accomplished?

A fundamental assumption is that no Insured will ever have more than one
Policy of a given type. How would I guarantee that not more than one
Policy
of a given type (PolicyType Code) ever appears on any Cert? How would I
guarantee the same thing for any two Certs assigned to the same Insured?

Thanks,
OldBlindPew