Self Referential Entity - MANY TO MANY

Just after some advice regarding this database design situation.

So I have two tables in the database.

Table 1: Patients Table 2: Claimants

Patients holds attributes data on a private patient, so details about the person, his/her birthday, names, medical conditions, etc etc.. Claimants is the entity who pays on behalf of the patient, so Claimant can be a patient himself, another person, a business (who pays for work injury), private healthcare provider, government bodies etc etc..

Patients and claimants have IDs who are foreign keys in other tables such as invoices, receipts etc...

One Patient can have multiple Claimants (More than one entity can pay on his behalf), each Claimant can have multiple patients.

On further investigation, I've identified that many of the attributes of Patients and Claimants over开发者_StackOverflowlap as a Patient can pay for himself thus is a private Claimant.

My thinking is to merge the two tables into one and simply call it accounts and have a claimantType field to identify the type of the account, be it private, healthcare, business or government.

What potential practical drawbacks do I need to keep in mind with this change? Apart from the changing the other linked tables in database?

EDIT: Just to make it clear, There's already a junctional table PatientClaimants which basically just map the patients to the claimants. Thanks!

Merging these two tables I believe is wrong.

A patient is always a human. So it cannot be a business or an organisation.

I believe here you have:

Address
=======
......

Person
=======
AddressId (FK)

BusinessEntity
==============
AddressId  (FK)

Patient
=======
PersonId (FK)

Claimant
========
PersonId  (FK)
BusinessEntityId  (FK)

Here PersonId or BusinessId one of them can be null.

You could either (a) put in an intersection table that relates patient IDs to claimant IDs, or (b) as you discussed, merge them together - but if you already have data out there that could be problematic.

You could also set up a demographics table that shows common data between patients and claimants and references an abbreviated patient/claimant table - this way you do not break your existing structure.